Image display and labeled device

ABSTRACT

An image display according to an embodiment includes a first image-displaying portion that displays first information about a certain object as a first image of object color, and a second image-displaying portion that displays second information about the object as a second image of structural color provided by a relief structure, the relief structure including at least one structure selected from the group consisting of diffraction grating, hologram, and light-scattering structure having an anisotropic light-scattering property. According to an example, the object is a person, and the first image includes a facial image of the person. A labeled article according to another embodiment includes the image display, and a substrate supporting the image display.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of U.S. application Ser.No. 13/362,480, filed Jan. 31, 2012, which is a continuation of PCTApplication No. PCT/JP2010/063327, filed Aug. 5, 2010 and based upon andclaiming the benefit of priority from prior Japanese Patent ApplicationsNo. 2009-187654, filed Aug. 13, 2009; No. 2010-034799, filed Feb. 19,2010; No. 2010-034800, filed Feb. 19, 2010; and No. 2010-066885, filedMar. 23, 2010, the entire contents of all of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image display technique.

2. Description of the Related Art

Many individual authentication media such as passport and identification(ID) card use facial images in order to allow individual authenticationwith visual check.

In the past, for example, a photographic paper having a facial imageprinted thereon was adhered to a booklet so as to issue a passport. Sucha passport, however, may be tampered by replacing the photographicprinting with another one.

For this reason, in recent years, information about the facial imagetends to be digitalized, and the digitalized information is reproducedon the booklet. For example, thermal transfer recording method using atransfer ribbon is considered as the method for reproducing the image.

However, printers of thermal transfer recording method using sublimationdye or colored thermoplastic resin are widely available in recent years.In view of such circumstances, it is not necessarily difficult to removethe facial image from the passport and record another facial imagethereon.

Jpn. Pat. Appln. KOKAI Publication No. 2000-141863 describes that afacial image is recorded by the above method, and the same facial imageis further recorded thereon using fluorescent ink. Jpn. Pat. Appln.KOKAI Publication No. 2002-226740 describes that a facial image isrecorded using ink containing colorless or light-colored fluorescent dyeand colored pigments. Jpn. Pat. Appln. KOKAI Publication No. 2003-170685describes that an ordinary facial image and a facial image formed withpearl pigments are arranged side by side.

When these techniques are applied to a passport, it is difficult totamper with the passport. However, the facial image recorded usingfluorescent material cannot be perceived unless a special light sourcesuch as an ultraviolet lamp is used. Although the facial image formedwith pearl pigments can be perceived with unaided eyes, the particlesizes of pearl pigments are large, and therefore, it is difficult toform a high-resolution image using this.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide an image display thatdisplays a high quality image and is hard to tamper with informationthereon.

According to a first aspect of the present invention, there is providedan image display comprising a first image-displaying portion thatdisplays first information about a certain object as a first image ofobject color, and a second image-displaying portion that displays secondinformation about the object as a second image of structural colorprovided by a relief structure, the relief structure including at leastone structure selected from the group consisting of diffraction grating,hologram, and light-scattering structure having an anisotropiclight-scattering property.

According to a second aspect of the present invention, there is provideda labeled article comprising the image display according to the firstaspect, and a substrate supporting the image display.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a plan view schematically showing a labeled article accordingto the first embodiment of the present invention;

FIG. 2 is a cross sectional view schematically showing an example of astructure that can be employed is the labeled article shown in FIG. 1;

FIG. 3 is an enlarged plan view showing a part of the labeled articleshown in FIG. 1;

FIG. 4 is an enlarged plan view showing another part of the labeledarticle shown in FIG. 1;

FIG. 5 is a cross sectional view schematically showing an example of astructure that can be employed in a second image-displaying portionincluded in the labeled article shown in FIG. 1;

FIG. 6 is a plan view schematically showing a modification of thelabeled article shown in FIG. 1;

FIG. 7 is a cross sectional view schematically showing an example of astructure that can be employed in the labeled article shown in FIG. 6;

FIG. 8 is a cross sectional view schematically showing another exampleof a structure that can be employed in the labeled article shown in FIG.6;

FIG. 9 is a plan view schematically showing an example of a structurethat can be used to display a three-dimensional image;

FIG. 10 is a view schematically showing an example of a method ofshooting a three-dimensional image;

FIG. 11 is a cross sectional view schematically showing another exampleof a structure that can be employed in the labeled article shown in FIG.1;

FIG. 12 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 6;

FIG. 13 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 6;

FIG. 14 is a plan view schematically showing a labeled article accordingto the second embodiment of the present invention;

FIG. 15 is a cross sectional view schematically showing an example of astructure that can be employed in the labeled article shown in FIG. 14;

FIG. 16 is an enlarged plan view of a part of the labeled article shownin FIG. 14;

FIG. 17 is an enlarged plan view of another part of the labeled articleshown in FIG. 14;

FIG. 18 is an enlarged cross sectional view of a part of the labeledarticle shown in FIG. 14;

FIG. 19 is an enlarged cross sectional view of another part of thelabeled article shown in FIG. 14;

FIG. 20 is a cross sectional view schematically showing another exampleof a structure that can be employed in the labeled article shown in FIG.14;

FIG. 21 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14;

FIG. 22 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14;

FIG. 23 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14;

FIG. 24 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14;

FIG. 25 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14;

FIG. 26 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14;

FIG. 27 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14;

FIG. 28 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14;

FIG. 29 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14;

FIG. 30 is a plan view schematically showing an example of a structurethat can be employed in an image-displaying portion producing structuralcolor using light scattering;

FIG. 31 is a perspective view schematically showing another example of astructure that can be employed in an image-displaying portion producingstructural color using light scattering;

FIG. 32 is a perspective view schematically showing still anotherexample of a structure that can be employed in an image-displayingportion producing structural color using light scattering;

FIG. 33 is a perspective view schematically showing an example of astructure that can be employed in an image-displaying portion displayingdark color as structural color;

FIG. 34 is a view schematically showing an example of a manufacturingapparatus that can be used to manufacture the labeled article shown inFIG. 14;

FIG. 35 is a view schematically showing an example of a transfer foilthat can be used for manufacturing the labeled article shown in FIG. 14;

FIG. 36 is a plan view schematically showing an individualauthentication medium according to the third embodiment of the presentinvention;

FIG. 37 is an enlarged plan view showing a part of the image displayincluded in the labeled article of FIG. 36;

FIG. 38 is a cross sectional view taken along the line XXXVIII-XXXVIIIof the image display shown in FIG. 37;

FIG. 39 is an enlarged plan view showing another part of the imagedisplay included in the labeled article shown in FIG. 36;

FIG. 40 is a cross sectional view taken along the line LX-LX of theimage display shown in FIG. 39;

FIG. 41 is a cross sectional view schematically showing an example of aprimary transfer foil that can be used for manufacturing the labeledarticle shown in FIGS. 36 to 40;

FIG. 42 is a plan view schematically showing an example of a structurethat can be employed in the primary transfer foil shown in FIG. 41;

FIG. 43 is a cross sectional view schematically showing an example of asecondary transfer foil that can be manufactured using the primarytransfer foil shown in FIG. 41;

FIG. 44 is a cross sectional view schematically showing an example of aused primary transfer foil;

FIG. 45 is a plan view schematically showing an example of a diffractionstructure that can be employed in the image display of the labeledarticle shown in FIGS. 36 to 39;

FIG. 46 is a plan view schematically showing an example of a diffractionstructure that can be used in combination with the diffraction structureshown in FIG. 45;

FIG. 47 is a plan view schematically showing an example of anarrangement of the diffraction structure shown in FIGS. 45 and 46;

FIG. 48 is a plan view schematically showing another example of anarrangement of the diffraction structure shown in FIGS. 45 and 46;

FIG. 49 is a plan view schematically showing an example of an imagedisplay that employs the arrangement shown in FIG. 48;

FIG. 50 is a plan view schematically showing an image displayed by theimage display shown in FIG. 49;

FIG. 51 is a plan view schematically showing another image displayed bythe image display shown in FIG. 49;

FIG. 52 is a plan view schematically showing an example of an image thatcan be displayed by an image display employing the arrangement shown inFIG. 48;

FIG. 53 is a plan view schematically showing another example of an imagedisplay that employing the arrangement shown in FIG. 48;

FIG. 54 is a plan view schematically showing still another example of animage display that employing the arrangement shown in FIG. 48;

FIG. 55 is a plan view schematically showing an example of an imagedisplay that employs a configuration similar to an image displayaccording to the fourth embodiment of the present invention;

FIG. 56 is a plan view schematically showing one of the images displayedby the image display shown in FIG. 55;

FIG. 57 is a plan view schematically showing another image displayed bythe image display shown in FIG. 55;

FIG. 58 is a plan view schematically showing one of the images that canbe displayed when the image display shown in FIG. 55 employs morecomplicated structure;

FIG. 59 is a plan view schematically showing another image that can bedisplayed by the image display displaying the image shown in FIG. 58;

FIG. 60 is a plan view schematically showing another image that can befurther displayed by the image display displaying the image shown inFIG. 58;

FIG. 61 is a plan view schematically showing an example of anarrangement of a diffraction structure that can be employed in the imagedisplay displaying the image shown in FIGS. 58 to 60;

FIG. 62 is a plan view schematically showing another example of anarrangement of a diffraction structure that can be employed in the imagedisplay displaying the image shown in FIGS. 58 to 60;

FIG. 63 is a plan view schematically showing still another example of anarrangement of a diffraction structure that can be employed in the imagedisplay displaying the image shown in FIGS. 58 to 60;

FIG. 64 is a plan view schematically showing an example of a structurethat can be employed in the image display of the labeled articleaccording to the fourth embodiment of the present invention;

FIG. 65 is a plan view schematically showing one of the images displayedby the image display shown in FIG. 64;

FIG. 66 is a plan view schematically showing another image displayed bythe image display shown in FIG. 64;

FIG. 67 is a plan view schematically showing still another imagedisplayed by the image display shown in FIG. 64;

FIG. 68 is a plan view schematically showing an example of an image thatcan be displayed when the image display of the labeled article accordingto the fourth embodiment of the present invention employs anotherstructure;

FIG. 69 is a plan view schematically showing another image that can bedisplayed by the image display displaying the image shown in FIG. 68;

FIG. 70 is a plan view schematically showing still another image thatcan be displayed by the image display displaying the image shown in FIG.68;

FIG. 71 is a view schematically showing an example of conditions thatallow images to be perceived when the grooves of the diffraction gratinghave straight shapes;

FIG. 72 is a view schematically showing an example of conditions thatallow images to be perceived when the grooves of the diffraction gratingare curved lines;

FIG. 73 is an enlarged plan view showing one of the diffractionstructures included in the image display shown in FIG. 72;

FIG. 74 is an enlarged plan view showing another diffraction structureincluded in the image display shown in FIG. 72;

FIG. 75 is an enlarged plan view showing one of the diffractionstructures that can be included in the image display according to amodification;

FIG. 76 is an enlarged plan view showing another diffraction structurethat can be included in the image display including the diffractionstructure shown in FIG. 75;

FIG. 77 is a plan view schematically showing one of the images that canbe displayed by the image display according to another modification;

FIG. 78 is a plan view schematically showing another image that can bedisplayed by the image display displaying the image shown in FIG. 77;and

FIG. 79 is a plan view schematically showing another image that can befurther displayed by the image display displaying the image shown inFIG. 77.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be hereinafter described indetail with reference to drawings. It should be noted that constituentelements achieving the same or similar functions are denoted with thesame reference numerals throughout the drawings, and redundantexplanation thereof is omitted.

First Embodiment

The first embodiment relates to, for example, the following techniques.

(1) An image display comprising a first image-displaying portion thatdisplays first information about a certain object as a first image ofobject color, and a second image-displaying portion that displays secondinformation about the object as a second image of structural colorprovided by a relief structure, the relief structure including at leastone structure selected from the group consisting of diffraction grating,hologram, and light-scattering structure having an anisotropiclight-scattering property.(2) The image display according to the item (1), wherein when seen in adirection perpendicular to a display surface, the first and secondimage-displaying portions do not overlap each other.(3) The image display according to the item (1), wherein when seen in adirection perpendicular to a display surface, the first and secondimage-displaying portions completely overlap each other.(4) The image display according to the item (1), wherein when seen in adirection perpendicular to a display surface, the first and secondimage-displaying portions partially overlap each other.(5) The image display according to any one of the items (1) to (4),wherein the second image-displaying portion includes dot-shapedportions, and each center of the dot-shaped portions is located on alattice point of a virtual planar lattice.(6) The image display according to any one of the items (1) to (5),wherein the object is a person.(7) The image display according to the item (6), wherein the first andsecond images include the same pattern.(8) The image display according to the item (6), wherein the first andsecond images include the same facial image.(9) The image display according to any one of the items (1) to (8),wherein the size of the first image-displaying portion is 0.1 to 30times the size of the second image-displaying portion.(10) The image display according to any one of the items (1) to (9),wherein the second image-displaying portion has a visiblelight-transmitting property.(11) The image display according to any one of the items (1) to (10),wherein the second image-displaying portion includes a layered structureincluding a first low refractive index layer having a visiblelight-transmitting property and a first high refractive index layerhaving a refractive index higher than that of the first low refractiveindex layer.(12) The image display according to the item (11), wherein the firsthigh refractive index layer is made of at least one material selectedfrom the group consisting of metal, metal oxide, intermetallic compound,and resin.(13) The image display according to any one of the items (1) to (12),further comprising a diffraction/scattering layer for diffracting orscattering external light.(14) The image display according to the item (13), wherein thediffraction/scattering layer has a visible light-transmitting propertyand at least partially faces a front surface of the firstimage-displaying portion.(15) The image display according to the item (14), wherein thediffraction/scattering layer includes a layered structure including asecond low refractive index layer having a visible light-transmittingproperty and a second high refractive index layer having a refractiveindex higher than that of the second low refractive index layer.(16) The image display according to the item (14), wherein the secondhigh refractive index layer is made of at least one material selectedfrom the group consisting of metal, metal oxide, intermetallic compound,and resin.(17) A labeled article comprising the image display according to any oneof the items (1) to (16), and a substrate supporting the image display.(18) The labeled article according to the item (17), wherein the labeledarticle is an individual authentication medium.

The effects of the techniques according to the items (1) to (17) will beindividually described.

In the image display according to the item (1), the first informationabout the certain object is displayed as a first image of object color.The first image of object color has excellent visibility.

In the image display according to the item (1), the second informationabout the above object is displayed as the second image of structuralcolor provided by the relief structure. The relief structure includes atleast one structure selected from the group consisting of diffractiongrating, hologram, and light-scattering structure having anisotropiclight-scattering property. The color of the image displayed by thediffraction grating or the hologram changes according to the observationdirection or the illumination direction. The light-scatteringperformance of the light-scattering structure having the anisotropiclight-scattering property changes according to the illuminationdirection. Therefore, this image display provides special visualeffects. It is extremely difficult to tamper with the informationdisplayed by the hologram, the diffraction grating or thelight-scattering structure.

It should be noted that an “object color” is a color produced by a bulkmaterial having smooth surface. When particular white light is used asthe illumination light, the “object color” is determined by theabsorption spectrum and the reflectance spectrum of the material itselfthat makes up the object.

On the other hand, a “structural color” is a color provided by thestructure of the object. The “structural color” is generated by, forexample, at least one of light diffraction and light scattering.Alternatively, the “structural color” is generated by confining light.

In the image display according to the item (2), the first and secondimage-displaying portions do not overlap each other when seen in adirection perpendicular to the display surface. Therefore, with theimage display according to the item (2), one of the first and secondimages does not reduce the visibility of the other of the first andsecond images.

In the image display according to the item (3), the first and secondimage-displaying portions completely overlap each other when seen in adirection perpendicular to the display surface. The secondimage-displaying portion has, for example, a light-transmittingproperty, and is interposed between the first image-displaying portionand the observer. Therefore, the observer visually recognizes only thefirst image when the intensity of the diffracted light from the reliefstructure or the scattered light is low. When the intensity of thediffracted light from the relief structure or the scattered light ishigh, the observer visually recognizes only the second image, orvisually recognizes the superposition of the first image and the secondimage. Therefore, for example, when the first and second images includethe same pattern, and at least one of the illumination direction and theobservation direction is changed, at least a part of the image displayedby this image display can change the color between object color andstructural color without changing the pattern.

In the image display according to the item (4), the first and secondimage-displaying portions partially overlap each other when seen in adirection perpendicular to the display surface. The secondimage-displaying portion has, for example, a light-transmittingproperty, and is interposed at least partially between the firstimage-displaying portion and the observer. Therefore, the observervisually recognizes only the first image when the intensity of thediffracted light from the relief structure or the scattered light islow. When the intensity of the diffracted light from the reliefstructure or the scattered light is high, the observer visuallyrecognizes only the second image, visually recognizes an image includinga part of the first image and the second image, or visually recognizesan image including the superposition of the first image and the secondimage. Therefore, for example, when the first and second imagesrespectively include the first and second patterns, and the first andsecond patterns are different from each other, the image displayed bythe image display changes as follows. When at least one of theillumination direction and the observation direction is changed, theimage displayed by the image display can change both of the pattern andthe color.

In the image display according to the item (5), the secondimage-displaying portion includes dot-shaped portions, and each centerof these dot-shaped portions is located on a lattice point of a virtualplanar lattice. When thermal transfer using a thermal head is utilized,the second image-displaying portion having such structure is obtained innormal cases.

In the image display according to the item (6), the object is a person.In other words, the first and second information include personalinformation of the same person. In this case, it is more difficult tocounterfeit the image display, and in addition, the image display can beused for individual authentication.

In the image display according to the item (7), the first and secondimages include the same pattern. Here, as an example, the image displaycan be verified by comparing the pattern of one of the first and secondimages with the pattern of the other of the first and second images.

In the image display according to the item (8), the first and secondimages include the same facial image. This image display can be usedfor, for example, individual authentication. Here, as an example, theimage display can be verified by comparing the first and second images.

In the image display according to the item (9), the firstimage-displaying portion has a size of area 0.1 to 30 times the size ofarea of the second image-displaying portion. In this case, it is easy tocompare the pattern of one of the first and second images with thepattern of the other of the first and second images.

In the image display according to the item (10), the secondimage-displaying portion has a visible light-transmitting property. Inthis case, the structure behind the second image-displaying portion maybe seen through. In other words, more complicated visual effects can beachieved.

In the image display according to the item (11), the secondimage-displaying portion includes a layered structure including a firstlow refractive index layer having a visible light-transmitting propertyand a first high refractive index layer having a refractive index higherthan that of the first low refractive index layer. This layeredstructure can be used as a reflection layer such as a reflection layerhaving a light-transmitting property. The reflection layer enhances thevisual effects given by the relief structure. When the reflection layerhas a light-transmitting property, the structure behind the secondimage-displaying portion may be seen through.

In the image display according to the item (12), the first highrefractive index layer is made of at least one material selected fromthe group consisting of metal, metal oxide, intermetallic compound, andresin. These materials are suitable for achieving high reflectanceand/or high transmittance.

The image display according to the item (13) further includes adiffraction/scattering layer for diffracting or scattering externallight. When the diffraction/scattering layer is provided, a morecomplicated image can be displayed by the image display.

In the image display according to the item (14), thediffraction/scattering layer has a visible light-transmitting property,and at least partially faces the front surface of the firstimage-displaying portion. In this case, the structure behind thediffraction/scattering layer may be seen through. In other words, morecomplicated visual effects can be achieved.

The diffraction/scattering layer according to the item (15) includes alayered structure including a second low refractive index layer having avisible light-transmitting property and a second high refractive indexlayer having a refractive index higher than that of the second lowrefractive index layer. This layered structure can be used as areflection layer such as a reflection layer having a light-transmittingproperty. The reflection layer enhances the visual effects given by therelief structure. When the reflection layer has a light-transmittingproperty, the structure behind the diffraction/scattering layer may beseen through.

In the image display according to the item (16), the second highrefractive index layer is made of at least one material selected fromthe group consisting of metal, metal oxide, intermetallic compound, andresin. These materials are suitable for achieving high reflectanceand/or high transmittance.

The labeled article according to the item (17) includes the imagedisplay according to any one of the items (1) to (16) and the substratesupporting this image display. Therefore, in the labeled article, highquality image is displayed by the image display, and in addition, it isdifficult to tamper with the information recorded on the image display.

The labeled article according to the item (18) is an individualauthentication medium. Since the individual authentication mediumincludes the above image display, the individual authentication mediumachieves excellent anti-counterfeiting effects.

Subsequently, the first embodiment will be described with reference todrawings.

FIG. 1 is a plan view schematically showing a labeled article accordingto the first embodiment of the present invention.

The labeled article 100 shown in FIG. 1 is a booklet such as a passportused as an individual authentication medium. FIG. 1 depicts a bookletwhen the booklet is open.

In the explanation below, an X direction and a Y direction aredirections parallel to a display surface of an image display andintersect each other. Typically, the X and Y directions areperpendicular to each other. A Z direction is a direction perpendicularto the X direction and the Y direction. In other words, the Z directionis a thickness direction.

This individual authentication medium 100 includes a cahier 1 and acover sheet 2.

The cahier 1 includes one or more paper slips 11. Typically, printpatterns 12 such as character strings and ground tints are provided onthe paper slips 11. The cahier 1 is formed by folding, in two, a paperslip 11 or a bundle of a plurality of paper slips 11. The paper slip 11may include, e.g., an IC (integrated circuit) chip on which personalinformation is to be recorded and an antenna which allows communicationwith the IC chip in a noncontacting manner.

The cover sheet 2 is folded in two. The cover sheet 2 and the cahier 1are laid such that the cahier 1 is sandwiched by the cover sheet 2 whenthe booklet is closed. The cover sheet 2 and the cahier 1 are integratedby, e.g., binding them together at positions of creases thereof.

The cover sheet 2 displays an image including personal information. Thispersonal information includes individual authentication information usedfor individual authentication. This personal information can beclassified into, for example, biometric information and non-biometricpersonal information.

The biometric information is one of features of a living body that isunique to the individual. Typically, the biometric information is afeature that can be distinguished by an optical method. For example, thebiometric information is at least one image or pattern of a face, afingerprint, an iris and a vein.

The non-biometric personal information is personal information otherthan the biometric information. The non-biometric personal informationis, for example, at least one of name, birth date, age, blood type,gender, nationality, address, domicile of origin, phone number,affiliation, and status. The non-biometric personal information maycontain the characters entered by typewriting, may contain charactersthat are entered by mechanically-reading a hand-written characters suchas a signature, or may contain both of them.

In FIG. 1, the cover sheet 2 displays images I1 a, I1 b, and I2. In FIG.2, reference symbols Aa and Ab represent regions corresponding to theimages I1 a and I1 b, respectively.

The images I1 a and I2 are images of object color. In this case, “objectcolor” is a color represented using absorption and reflection of lightas described above. More specifically, an “object color” produced by acertain object is a color corresponding to optical properties ofmaterials that make up the object such as a reflectance spectrum and atransmittance spectrum.

The images I1 a and I2 can be visually recognized when they areilluminated with white light and observed with unaided eyes. One of theimages I1 a and I2 may be omitted.

The images I1 a and I2 can be made with, e.g., at least one of dye andpigment or a mixture including a transparent resin and at least one ofdye and pigment. In this case, the images I1 a and I2 can be formed bythermal transfer recording method using a thermal head, an ink jetrecording method, an electrophotographic method, or a combination of twoor more of them. Alternatively, the images I1 a and I2 can be formed byforming a layer including a heat-sensitive color-producing agent anddrawing on this layer with laser beam. Alternatively, the images I1 aand I2 can be formed by photography. Alternatively, a combination ofthese methods may be used. At least a part of the image I2 may be formedby thermal transfer recording method using a hot stamp, may be formed bya printing method, or may be formed using a combination of them.

The image I1 b is an image of structural color. In this case,“structural color” is a color provided by the structure of the object asdescribed above. The “structural color” is a color displayed by usingrefraction, diffraction, interference, reflection, or a combination oftwo or more of them. More specifically, the “structural color” producedby a certain object is a color that varies depending on opticalproperties of materials of the object such as a refractive spectrum andabsorption spectrum, the structure of the object such as the shape ofthe surface or the interface, and the thickness and the number oflayers. Typically, an object that produces the “structural color” ismade of a transparent material, a material that can have metallicluster, or a combination thereof.

The “structural color” can be produced by, for example, hologram,diffraction grating, light-scattering structure, or a combination of twoor more of them. A structure in which recessed portions and/orprotruding portions are arranged regularly or irregularly can achieve aneffect of confining incident light when a ratio of depth or height withrespect to a width or a diameter of the recessed portion and theprotruding portion is sufficiently large, and a pitch of the recessedportions and/or protruding portions is sufficiently small. In otherwords, a low reflectivity can be achieved. The “structural color” may beproduced by such structure or a combination of such structure and one ormore of hologram, diffraction grating, and light-scattering structure.Here, as an example, it is assumed that the image I1 b is an imagedisplayed by the diffraction grating.

The image I1 b is formed by, for example, thermal transfer recordingmethod using a thermal head. Alternatively, the image I1 b may be formedby performing thermal transfer recording using a thermal head andthermal transfer recording using a hot stamp or a heat roll in order.

The images I1 a and I1 b include facial images of the same person. Thefacial image included in the image I1 a and the facial image included inthe image I1 b may be the same or may be different. The facial imageincluded in the image I1 a and the facial image included in the image I1b may be of the same size or may be of different sizes. Alternatively,each of the images I1 a and I1 b may include other biometric informationinstead of the facial image, and may further include biometricinformation other than the facial image in addition to the facial image.

The image I1 b may include non-biometric personal information instead ofthe biometric information, and may further include non-biometricpersonal information in addition to the biometric information. The imageI1 b may include non-personal information in addition to the personalinformation.

The image I2 includes non-biometric personal information andnon-personal information. The image I2 constitutes, for example, one ormore of characters, symbols, signs, and marks.

Subsequently, the structure of the cover sheet 2 will be described withreference to FIGS. 2 to 4.

FIG. 2 is a cross sectional view schematically showing an example of astructure that can be employed is the labeled article shown in FIG. 1.FIG. 3 is an enlarged plan view showing a part of the labeled articleshown in FIG. 1. FIG. 4 is an enlarged plan view showing another part ofthe labeled article shown in FIG. 1.

As shown in FIG. 2, the cover sheet 2 includes a cover sheet main body21 and an image display 22.

The cover sheet main body 21 is a substrate of the individualauthentication medium 100. The cover sheet main body 21 is folded in twoso as to sandwich the cahier 1 when the labeled article 100 is closed.

Typically, the cover sheet main body 21 is a paper slip. The cover sheetmain body 21 may have a single-layer structure, or may have a multilayerstructure. The cover sheet main body 21 may be, for example, plainpaper, coated paper, or synthetic paper. The synthetic paper may be, forexample, a composite material made by bonding paper and a film made ofresin such as polypropylene and polystyrene.

The color of the cover sheet main body 21 may be a single color, or acombination of a plurality of colors. In the latter case, the coversheet main body 21 preferably includes white pigments such as titaniumwhite, magnesium carbonate, zinc oxide, barium sulfate, silica, talc,clay, or calcium carbonate, so that the image display 22 can display animage with excellent visibility.

The thickness of the cover sheet main body 21 is usually within a rangeof 20 μm to 1000 μm, and preferably within a range of 50 μm to 800 μm.

The image display 22 is a layer having a multilayer structure. The imagedisplay 22 is adhered to one of the main surfaces of the cover sheetmain body 21 that faces the cahier 1 when the labeled article 100 isclosed.

The image display 22 includes image display layers 220 a and 220 b, anadhesive layer 225, and a protective layer 227.

The image display layer 220 a is a first image-displaying portion thatdisplays first information about a certain object as the first image I1a of object color. In this case, the image display layer 220 a has apatterned shape corresponding to image I1 a shown in FIGS. 2 and 3. Thisimage display layer 220 a may be made with at least one of dye andpigment and optionally resin. This image display layer 220 a can beobtained by, for example, thermal transfer recording method using athermal head, ink jet recording method, electrophotographic method, or acombination of two or more of them. The image display layer 220 a formedby thermal transfer recording method using a thermal head is made of,for example, a plurality of dot-shaped portions arranged in atwo-dimensional manner shown in FIG. 3.

The image display layer 220 b is a second image-displaying portion thatdisplays second information about the above object as the second imageI1 b of structural color provided by the relief structure. Here, theimage display layer 220 b includes hologram and/or diffraction gratingas a relief structure, and has the patterned shape corresponding to theimage I1 b shown in FIGS. 2 and 4. In this case, as an example, theimage display layer 220 b is assumed to include a diffraction grating asa relief structure.

The image display layer 220 b can be formed by, for example, thermaltransfer recording method using a thermal head. The image display layer220 b formed by thermal transfer recording method using a thermal headis made of, for example, a plurality of dot-shaped portions arranged ina two-dimensional manner shown in FIG. 4. In this case, in a typicalcase, each of these dot-shaped portions plays a role of a pixel or asub-pixel.

The pixel or sub-pixel may have various shapes. The shape of the pixelor sub-pixel seen from the Z direction is, for example, a circularshape, an elliptical shape, or a polygonal shape such as a triangularshape and a rectangular shape. In one or more pixels or sub-pixels, atleast a part of the relief structure may be destroyed or deformed. Inother words, the size of area in which structural color is displayed maybe different among the pixels or the sub-pixels.

The surface of the pixels or the sub-pixels on the observer's side maybe flat, or may include protruding portions or recessed portions. Theprotruding or recessed portion may have a cylindrical or square pillarshape. Alternatively, the protruding or recessed portion may have aconical shape or a pyramid shape such as a triangular pyramid, a squarepyramid, a pentagonal pyramid, and a six-sided pyramid. Alternatively,the protruding or recessed portion may have a shape of a combination ofcylindrical and conical shapes, or a shape of combination of a squarepillar and a pyramid. Alternatively, the protruding or recessed portionmay have a hemispherical shape, a semi-elliptical shape, or a bellshape. The entire surface of the pixels or sub-pixels on the observer'sside may be a protruding surface or a recessed surface, or only a partof the surface of the pixels or sub-pixels on the observer's side may bea protruding surface or a recessed surface. The surface of the pixels orsub-pixels on the observer's side may include only one of the protrudingportion or the recessed portion, or may include a plurality ofprotruding portions or a plurality of recessed portions.

The distance between the pixels or the sub-pixels is, for example, 300μm or less. When this distance is long, it is difficult to display theimage I1 b with excellent visibility. The lower limit value of thisdistance is zero. However, when the distance between the pixels or thesub-pixels is too short, display unevenness may occur.

The thickness of the image display layer 220 b is, for example, within arange of 0.1 μm to 2.0 μm. The image display layer 220 b may haveuniform thickness, or the thickness may be different among the pixels orsub-pixels.

Typically, the image display layer 220 b has a multilayer structure. Thedetailed structure of the image display layer 220 b will be describedlater.

The size of the image display layer 220 a is preferably 1 to 30 timesthe size of the image display layer 220 b. This will be described below.

For example, when the image I1 a is a color facial image, the facialimage is generally represented using dots with 175 dots/inch. In otherwords, in this case, the size of the dot constituting the image I1 a isgenerally 145 μm. This is because, in general, when the density of thedots is higher than 175 dots/inch, improvement of resolution cannot beperceived by observation with unaided eyes even if the density of dotsis further increased.

Each dot-shaped portion constituting the image display layer 220 b needsto have a size of, for example, 5 μm or more. This is because when thesize of the dot-shaped portion is excessively reduced, the function ofthe diffraction grating may be lost.

Therefore, when it is assumed that the number of pixels of the image I1a and the number of pixels of the image I1 b are the same, the size ofthe image display layer 220 b is preferably 1/30 or more than 1/30 ofthe size of the image display layer 220 a. In other words, the size ofthe image display layer 220 a is preferably equal to or less than 30times the size of the image display layer 220 b.

Since the image I1 b is displayed with the diffraction grating, theimage I1 b is preferably observed at a relatively small viewing angle.When the image I1 b is excessively large, it is difficult to observe theimage I1 b at a relatively small viewing angle. Therefore, the size ofthe image display layer 220 b is preferably 10 times or less than 10times the size of the image display layer 220 a. In other words, thesize of the image display layer 220 a is preferably equal to or lessthan 0.1 times the size of the image display layer 220 b.

The protective layer 227 faces the cover sheet main body 21 with theimage display layers 220 a and 220 b interposed therebetween. Therelease protective layer 227 has a light-transmitting property, and istransparent in a typical case. The protective layer 227 may be omitted.

The protective layer 227 is made of, for example, a resin such asthermoplastic resins, thermosetting resins, and ultraviolet or electroncurable resin. When a transfer foil is used to adhere the image display22 to the cover sheet main body 21, it is preferable to use athermoplastic resin in view of flexibility and foil cutting property.

Thermoplastic resin may be, for example, polyacrylic ester resin,chlorinated rubber resin, vinyl chloride-vinyl acetate copolymer resin,cellulose resin, chlorinated polypropylene resin, epoxy resin, polyesterresin, nitrocellulose resin, styrene acrylate resin, polyether resin,polycarbonate resin, or a mixture thereof. In view of foil cuttingproperty and wear resistant property, this resin may be added with oneor more of slip additives such as wax including petroleum wax andplant-based wax, higher fatty acid such as stearic acid, metal salt orester thereof, and silicone oil; an organic filler made of an organicmaterial such as polytetrafluoroethylene, polyethylene, silicone resin,and polyacrylonitrile; and an inorganic filler made of an inorganicmaterial such as silica.

The thickness of the protective layer 227 is, for example, within arange of 1 μm to 20 μm. In the case where the protective layer 227 isthin, when the protective layer 227 is partially removed in order totamper with information, there is a possibility that this may be noticedby observing the image display 22 with unaided eyes. On the other hand,in the case where the protective layer 227 is thick, when thecommercially available film is attached to the removed portion, it maybe impossible to notice the fact by observing the image display 22 withunaided eyes that the protective layer 227 is partially replaced withthe commercially available film.

The protective layer 227 may have in-plane uniformity of opticalproperty. Alternatively, the protective layer 227 may have in-planeunevenness of optical property.

The protective layer 227 may include one or more items selected from thegroup consisting of hologram, diffraction grating, infrared absorbinglayer, fluorescence layer, and print pattern providing object color.When the protective layer 227 is partially removed, this can be readilynoticed. It should be noted that the infrared absorbing layer and thefluorescence layer may be a continuous film, or may be patterned in agrid shape, an island shape, or a stripe shape. In the latter case, theprotective layer 227 employs, for example, a multilayer structureincluding a patterned infrared absorbing layer or fluorescence layer anda light-transmitting layer supporting this.

The adhesive layer 225 is interposed between the cover sheet main body21 and each of the image display layers 220 a and 220 b and between thecover sheet main body 21 and the protective layer 227. The adhesivelayer 225 may be transparent or opaque.

The adhesive layer 225 is made of, for example, thermoplastic resin. Thematerials of the adhesive layer 225 may be, for example, urethane resin,butyral resin, polyester resin, vinyl chloride resin such as polyvinylchloride and vinyl chloride-vinyl acetate copolymer, polyurethane resin,epoxy resin, chlorinated polypropylene, acrylic resin, polystyrene,polyvinyl benzene, styrene-butadiene copolymer resin, vinyl resin suchas polyvinyl resin obtained from styrene and alkyl methacrylates (thenumber of carbons of the alkyl group is 2 to 6), rubber-based material,or a mixture containing two or more of them.

The adhesive layer 225 may be added with one or more of wax, higherfatty acid such as stearic acid, metal salt and ester thereof,plasticizer, an organic filler made of an organic material such aspolytetrafluoroethylene, polyethylene, silicone resin, andpolyacrylonitrile, and an inorganic filler made of an inorganic materialsuch as silica.

The adhesive layer 225 may be a constituent element of the image display22, or may not be a constituent element of the image display 22. Theadhesive layer 225 may be omitted.

A part of the cover sheet 2 corresponding to the image I2 may employ,for example, substantially the same structure as that described for theportion corresponding to the image I1 a except that the displayed imageis different. Parts of the cover sheet 2 corresponding to the images I1a and I2 may have the same layered structure, or may have differentlayered structures.

Subsequently, the structure of the image display layer 220 b will bedescribed with reference to FIG. 5.

FIG. 5 is a cross sectional view schematically showing an example of astructure that can be employed in a second image-displaying portionincluded in the labeled article shown in FIG. 1.

As shown in FIG. 5, the image display layer 220 b includes a reliefstructure formation layer 223 b, a reflection layer 224 b, and anadhesive layer 225 b.

The relief structure formation layer 223 b is a layer having a mainsurface on which a relief structure is provided. This relief structureincludes, for example, at least one of diffraction grating and hologramas a diffraction structure. This relief structure displays the secondimage I1 b of structural color described above.

The relief structure formation layer 223 b includes, for example, firstto third portions producing different colors when they are illuminatedwith white light in a particular illumination direction and observed ina particular observation direction. The first to third portions aredifferent from each other in at least one of the grating constant andthe lengthwise direction of the grooves of the diffraction grating.Under a particular observation condition, the first to third portionsproduce, for example, blue, green, and red colors, respectively.

The relief structure formation layer 223 b may have a light-transmittingproperty or may not have a light-transmitting property. Typically, therelief structure formation layer 223 b has a light-transmittingproperty.

The material of the relief structure formation layer 223 b is, forexample, a resin such as photo-curable resin, thermosetting resin, andthermoplastic resin. The photo-curable resin is, for example,polycarbonate resin, acrylic resin, fluorine resin, silicone acrylicresin, epoxy acrylate resin, polystyrene resin, cycloolefin polymer,methylstyrene resin, fluorene resin, polyethylene terephthalate resin,or polypropylene resin. Thermosetting resin is, for example,styrene-acrylonitrile copolymer resin, phenol resin, melamine resin,urea resin, or alkyd resin. Thermoplastic resin is, for example,polypropylene resin, polyethylene terephthalate resin, or polyacetalresin. The hardened materials of these resins have a light-transmittingproperty, and the refractive indices thereof are generally about 1.5.

The reflection layer 224 b is formed on the relief structure formationlayer 223 b. The reflection layer 224 b covers at least a part of thesurface of the relief structure formation layer 223 b on which therelief structure is provided. Although the reflection layer 224 b may beomitted, the visibility of the image produced by the diffractionstructure improves when the reflection layer 224 b is provided.

The reflection layer 224 b may be, for example, a transparent reflectionlayer or an opaque metal reflection layer. The reflection layer 224 bcan be formed by, for example, vacuum deposition method such as vacuumevaporation and sputtering. When the reflection layer 224 b includesresin, the reflection layer 224 b may be formed using application orprinting.

When a transparent reflection layer is used as the reflection layer 224b, patterns of pictures, characters, and the like can be seen from thefront side of the image display 22 even if they are arranged on the backside of the reflection layer 224 b.

The transparent reflection layer may be, for example, a layer made of atransparent material whose refractive index is different from that ofthe relief structure formation layer 223 b. The transparent reflectionlayer made of a transparent material may have a single-layer structureor a multilayer structure. In the latter case, the transparentreflection layer may be designed to cause multiple-beam interference. Inother words, the transparent reflection layer may be a multilayer filmincluding a low refractive index layer and a high refractive indexlayer.

Transparent materials that can be used for the transparent reflectionlayer include, for example, metal oxide, intermetallic compound, resin,metal oxide, and intermetallic compound. More specifically, thetransparent material may be, for example, Sb₂S₃, Fe₂O₃, TiO₂, CdS, CeO₂,ZnS, PbCl₂, CdO, Sb₂O₃, WO₃, SiO₂, Si₂O₃, In₂O₃, PbO, Ta₂O₃, ZnO, ZrO₂,Cd₂O₃, Al₂O₃, and Ge.

Typically, the transparent reflection layer of the single-layerstructure made of the transparent dielectric has a higher refractiveindex with respect to the light of the wavelength described above ascompared with the relief structure formation layer 223 b. The differencebetween these refractive indices is, for example, 0.2 or more. When thesingle-layer structure is employed as the transparent reflection layer,the thickness thereof is within a range of, for example, 10 nm to 1,000nm.

Alternatively, the transparent reflection layer may be a metal layer,e.g., a metal layer whose thickness is less than 20 nm. The material ofthe metal layer is, for example, an elemental metal such as chromium,nickel, cobalt, aluminum, iron, tin, titanium, silver, gold, and copper,or an alloy of the above metals. Although the metal layer has lightshielding property when it is thick, the metal layer becomes, forexample, transparent when the thickness of the metal layer is decreased.For example, when an aluminum layer whose thickness is within a range of20 to 40 nm is used, metallic luster can be observed under a certainobservation condition, but when the observation angle is changed, thebackground can be seen through.

A thicker metal layer can also be used as the transparent reflectionlayer. For example, a relatively thick metal layer is formed, and manyapertures having diameters or widths that can be hardly noticed withunaided eyes are formed in the relatively thick metal layer.Alternatively, this metal layer is patterned into, for example, apattern of dots or lines. As a result, the transparent reflection layermade of the metal material can be obtained.

As the material of the opaque metal reflection layer, for example, thematerials described for the metal layer that serves as the transparentreflection layer can be used. Typically, the opaque metal reflectionlayer is not provided with apertures having diameters or widths that canbe hardly noticed with unaided eyes, and has a thickness sufficient forshielding the light.

A layer including a transparent resin and particles dispersed within theresin may be used as the transparent reflection layer or the opaquereflection layer. For example, particles made of metal material such aselemental metal and alloy or particles made of transparent dielectricsuch as transparent metal oxide and transparent resin can be used as theparticles. Typically, the particles are made of a material having a highrefractive index such as titanium dioxide. In the transparent resin,flakes may be dispersed instead of dispersing the particles.

The adhesive layer 225 b is formed on the reflection layer 224 b. Theadhesive layer 225 b adheres the laminated body including the reliefstructure formation layer 223 b and the reflection layer 224 b to theprotective layer 227 shown in FIG. 2. The adhesive layer 225 b is madeof, for example, thermoplastic resin.

The material of the adhesive layer 225 b may be, for example, urethaneresin, butyral resin, polyester resin, vinyl chloride resin such aspolyvinyl chloride and vinyl chloride-vinyl acetate copolymer,polyurethane resin, epoxy resin, chlorinated polypropylene, acrylicresin, polystyrene, polyvinyl benzene, styrene-butadiene copolymerresin, vinyl resin such as polyvinyl resin obtained from styrene andalkyl methacrylates (the number of carbons of the alkyl group is 2 to6), rubber-based material, or a mixture containing two or more of them.

The adhesive layer 225 b may be added with one or more of wax, higherfatty acid such as stearic acid, metal salt and ester thereof,plasticizer, organic filler made of an organic material such aspolytetrafluoroethylene, polyethylene, silicone resin, andpolyacrylonitrile, and inorganic filler made of an inorganic materialsuch as silica.

The adhesive layer 225 b may be a constituent element of the imagedisplay 22, or may not be a constituent element of the image display 22.In this labeled article 100, the adhesive layer 225 b may be omitted.

This image display 22 displays a part of personal information usinghologram and/or diffraction grating. It is extremely difficult to tamperwith the personal information, in particular, biometric information,displayed by the hologram and/or the diffraction grating. In the casewhere the diffraction structure is used, a higher-resolution image canbe displayed as compared with the case of using pearl pigments. In otherwords, this image display 22 can display an image with an excellentquality, and it is difficult to tamper with the information.

This labeled article 100 can be manufactured by the following method,for example.

First, a booklet main body is prepared. The booklet main body includesthe cahier 1 and the cover sheet main body 21. The booklet main body hassubstantially the same structure as the labeled article 100 except thatthe image display 22 is omitted. A part of the image I2 shown in FIG. 1that corresponds to the non-personal information may be printed on thebooklet main body.

Subsequently, personal information such as name, address, and date ofbirth is printed on the cover sheet main body 21. This print processuses, for example, intaglio printing or offset printing. At thisoccasion, at least one of line screen, colored pattern, andmicro-letters may be further printed. When they are printed, ordinaryprinting ink may be used, or special inks such as optically variable inkand fluorescent ink may be used.

Subsequently, the adhesive layer 225 shown in FIG. 2 is formed on thecover sheet main body 21. For example, liquid adhesive including vinylchloride-vinyl acetate copolymer is applied to the cover sheet main body21 according to print process such as roll-coating and screen printing.Alternatively, a film having a surface coated with adhesive is adheredto the cover sheet main body 21.

In addition, in order to form the image display layers 220 a and 220 b,the facial image of a person is taken with a camera. Using image dataobtained by this, a first transfer foil for the image display layer 220a and a second transfer foil for the image display layer 220 b aremanufactured. It should be noted that the first transfer foil includes afirst transfer material layer and a first support body releasablysupporting the first transfer material layer. On the other hand, thesecond transfer foil includes a second transfer material layer and asecond support body releasably supporting the second transfer materiallayer.

The first transfer material layer includes a pattern corresponding tothe image I1 a displayed by the image display layer 220 a. This patterncan be formed by various kinds of methods such as printing method suchas inkjet printing, silver halide photographic method, dye sublimationmethod, hot melt transfer process, resin type pigment transfer method,and electrophotographic method. The image display layer 220 a may beformed on the adhesive layer 225 by print process instead of forming itusing a transfer foil.

Like the first transfer material layer, the second transfer materiallayer also includes a pattern corresponding to the image I1 b displayedby the image display layer 220 b. This pattern may be formed using, forexample, electron beam lithography apparatus. For example, thediffraction grating pattern is drawn on the photosensitive resin layerformed on the polyethylene terephthalate (PET) substrate with electronbeam based on the above image data. As the photosensitive resin, forexample, a resin containing thiazine sensitizing dye, hexavalentchromium compound, and water-soluble polymer is preferably used. Whenthis resin is used, the following effects can be obtained: the dissolvedstate of the sensitizing dye can be kept without drying in an ammoniaatmosphere, and the transmittance can be improved. When the electronbeam drawing process is finished, non-drawn portions of thephotosensitive resin is removed by developing process, and subsequently,washing and drying processes are performed. As a result, the reliefstructure formation layer 223 b shown in FIG. 5 is obtained. Thereafter,the reflection layer 224 b is formed on the relief structure formationlayer 223 b by vacuum evaporation method, for example. As describedabove, the second transfer material layer including the relief structureformation layer 223 b and the reflection layer 224 b is obtained.

Thereafter, at least a part of the first transfer material layer istransferred from the first support body to the cover sheet main body 21.In addition, at least a part of the second transfer material layer istransferred from the second support body to the cover sheet main body21. For example, the hot stamp method is used to transfer them. In thismanner, the image display layers 220 a and 220 b are obtained.

Further, for example, coating liquid containing acrylic resin is appliedto the image display layers 220 a and 220 b and the adhesive layer 225,so that the protective layer 227 shown in FIG. 2 is formed. When thecoating liquid is applied, for example, roll coating method or screenprinting method is used. Instead of applying the coating liquid, a filmserving as the protective layer 227 may be attached to the image displaylayers 220 a and 220 b and the adhesive layer 225.

The labeled article 100 described above can be modified in variousforms. Although an example where the relief structure includes thediffraction structure has been described here, the relief structure mayinclude a light-scattering structure having anisotropic light-scatteringproperty. Alternatively, the labeled article 100 may employ thefollowing configuration.

FIG. 6 is a plan view schematically showing a modification of thelabeled article shown in FIG. 1. FIG. 7 is a cross sectional viewschematically showing an example of a structure that can be employed inthe labeled article shown in FIG. 6.

The labeled article 100 shown in FIG. 6 displays an image I1 instead ofthe images I1 a and I1 b.

As shown in FIG. 7, in a labeled article 100, image display layers 220 aand 220 b completely overlap each other when seen in a directionperpendicular to the display surface. The image display layer 220 b hasa light-transmitting property, and is interposed between the imagedisplay layer 220 a and an observer.

Therefore, when the intensity of the diffracted light or the scatteredlight emitted by the relief structure is low, the observer sees only thefirst image I1 a described with reference to FIG. 1 as the image I1shown in FIG. 6. On the other hand, when the intensity of the diffractedlight or the scattered light emitted by the relief structure is high,the observer sees only the second image I1 b described with reference toFIG. 1 as the image I1 shown in FIG. 6, or sees the superposition of thefirst image I1 a and the second image I1 b.

Therefore, for example, when the images I1 a and I1 b are of the samepattern, and at least one of the illumination direction and theobservation direction is changed, the image I1 displayed by this imagedisplay 22 can change the color between object color and structuralcolor without changing the pattern.

FIG. 8 is a cross sectional view schematically showing another exampleof a structure that can be employed in the labeled article shown in FIG.6.

The structure shown in FIG. 8 is different from the structure describedwith reference to FIGS. 6 and 7 in that the image display layers 220 aand 220 b partially overlap each other when seen in a directionperpendicular to the display surface. Therefore, when overlappingportions of the images I1 a and I1 b include the same pattern, and atleast one of the illumination direction and the observation direction ischanged, a part of the image I1 displayed by the image display 22 canchange the color between object color and structural color withoutchanging the pattern. Alternatively, when the images I1 a and I1 brespectively include first and second patterns which are different fromeach other, and at least one of the illumination direction and theobservation direction is changed, both of the pattern and the color canbe changed in the image I1 displayed by this image display 22.

A configuration may be employed in which a three-dimensional image canbe displayed as the image I1 b.

FIG. 9 is a plan view schematically showing an example of a structurethat can be used to display a three-dimensional image.

In FIG. 9, reference symbols CO_(R) and CO_(L) denote right eye pixeland left eye pixel, respectively. Reference symbol G denotes a groove ofa diffraction grating.

An image display layer 220 b shown in FIG. 9 includes sub-pixels CO_(R)and CO_(L). Pixels each including the sub-pixels CO_(R) and CO_(L) arearranged in the X and Y directions.

Each of the sub-pixels CO_(R) and CO_(L) includes the diffractiongrating as a relief structure. The sub-pixels CO_(R) and CO_(L) have thesame structure except that the directions of the grooves G of thediffraction grating are different.

In each of the sub-pixels CO_(R) and CO_(L), the grooves G have the sameshape, and the grooves G are arranged parallel to each other with acertain pitch. In the sub-pixels CO_(R) and the sub-pixels CO_(L), theshapes and the pitches of the groove G are the same. In the exampleshown in FIG. 9, each groove G is curved in the form of a segment of acircle. Alternatively, these grooves G may not be curved.

In each of the sub-pixels CO_(R) and CO_(L), the lengthwise direction ofthe groove G is inclined with respect to the X and Y directions. In thesub-pixels CO_(R) and the sub-pixels CO_(L), the inclination angles thatthe lengthwise directions of the grooves G forms with the X or Ydirection are the same, but the lengthwise directions are inverselyinclined with respect to the X or Y direction.

Under particular diffuse illumination conditions, the diffractiongrating emits the diffracted light with the highest intensity in thedirection perpendicular to the lengthwise direction of the groove G.Therefore, when the above structure is employed, the direction in whichthe sub-pixel CO_(R) for the right eye emits the diffracted light withthe highest intensity and the direction in which the sub-pixel CO_(L)for the left eye emits the diffracted light with the highest intensitycan be made different from each other.

When the image display layer 220 b employs the structure of FIG. 9, itis possible by utilizing the above that a pixel group including thesub-pixels CO_(R) displays an image for the right eye and a pixel groupincluding the sub-pixels CO_(L) displays an image for the left eye. Forexample, the image for the right eye can be displayed by setting theintensity of the diffracted light emitted by some of the sub-pixelsCO_(R) at a level lower than the intensity of the diffracted lightemitted by the other sub-pixels CO_(R). On the other hand, the image forthe left eye can be displayed by setting the intensity of the diffractedlight emitted by some of the sub-pixels CO_(L) at a level lower than theintensity of the diffracted light emitted by the other sub-pixelsCO_(L). By doing so, the three-dimensional image can be displayed.

In FIG. 9, the diffraction grating array having the simple structure isdepicted for the sake of simplicity of explanation. Other configurationsmay also be employed in the diffraction grating array in order todisplay the three-dimensional image. For example, the diffractiongrating array may include not only the two kinds of sub-pixels CO_(R)and CO_(L) whose lengthwise directions of the grooves G have the sameinclination angle and are inversely inclined but also sub-pixels whoseinclination angles in the lengthwise directions of the grooves G aredifferent. The diffraction grating array for displaying thethree-dimensional image may employ the configuration capable ofdisplaying a color image.

The diffraction grating array for displaying the three-dimensional imagecan be designed using, for example, the following method.

FIG. 10 is a view schematically showing an example of a method ofshooting a three-dimensional image.

For shooting a three-dimensional image, for example, a plurality ofcameras C_(R), C_(C), and C_(L) are arranged on the same horizontalplane as shown in FIG. 10, and a subject S is shot at the same time withthese cameras C_(R), C_(C), and C_(L). Alternatively, it is possiblethat one camera moves on the horizontal plane, and the subject S is shotat a plurality of positions.

Subsequently, image data obtained by this shooting are processed. In thestructure shown in FIG. 9, the diffraction grating array is constitutedby the two kinds of sub-pixels CO_(R) and CO_(L), and therefore, onlythe image data obtained at two shooting positions are used. For example,the subject S is shot with the cameras C_(R) and C_(L) shown in FIG. 10,and the image data obtained therefrom are processed.

More specifically, regions corresponding to the sub-pixels CO_(R) of thestructure shown in FIG. 9 are selected from the image shot with thecamera C_(R) to obtain an element image for the right eye. On the otherhand, regions corresponding to the sub-pixels CO_(L) of the structureshown in FIG. 9 are selected from the image shot with the camera C_(L)to obtain an element image for the left eye. Then, these element imagesare superposed on each other so as to produce a composite image (notshown).

Subsequently, the grayscale level that is to be displayed by each of thesub-pixels CO_(R) and CO_(L) is determined from the composite image. Forexample, the size of area of the diffraction grating is determined ineach of the sub-pixels CO_(R) and CO_(L). Thus, the structure of thediffraction grating array that is to be formed is obtained.

The above-described labeled article 100 may also be modified to otherforms.

FIG. 11 is a cross sectional view schematically showing another exampleof a structure that can be employed in the labeled article shown inFIG. 1. FIG. 12 is a cross sectional view schematically showing stillanother example of a structure that can be employed in the labeledarticle shown in FIG. 6. FIG. 13 is a cross sectional view schematicallyshowing still another example of a structure that can be employed in thelabeled article shown in FIG. 6.

The labeled article 100 shown in FIG. 11 is the same as the labeledarticle 100 described with reference to FIGS. 1 to 5 except that thelabeled article 100 shown in FIG. 11 further includes an opticalvariable layer 229. The labeled article 100 shown in FIG. 12 is the sameas the labeled article 100 described with reference to FIGS. 6 to 7except that the labeled article 100 shown in FIG. 12 further includesthe optical variable layer 229. The labeled article 100 shown in FIG. 13is the same as the labeled article 100 described with reference to FIG.8 except that the labeled article 100 shown in FIG. 13 further includesthe optical variable layer 229.

The optical variable layer 229 is interposed between the image displaylayer 220 a and the protective layer 227 and between the adhesive layer225 and the protective layer 227. The optical variable layer 229 doesnot overlap the image display layer 220 b.

The optical variable layer 229 is a diffraction/scattering layer thatdiffracts or scatters light. The optical variable layer 229 has, forexample, a light-transmitting property. The hue or brightness of thedisplay color of the optical variable layer 229 is changed when changingat least one of illumination direction and observation direction. Theoptical variable layer 229 displays an image that can be distinguishedfrom an image I1 b displayed by the image display layer 220 b.

The optical variable layer 229 is, for example, a light-transmittinglayer provided with a relief structure on a main surface thereof. Thisrelief structure includes, for example, at least one structure selectedfrom the group consisting of diffraction grating, hologram, andlight-scattering structure having anisotropic light-scattering property.Alternatively, the optical variable layer 229 is a multilayer filmobtained by stacking a plurality of layers having different refractiveindices so as to cause multiple-beam interference.

When the optical variable layer 229 is provided, the image display 22can display more complicated image. Therefore, it is more difficult totamper with the information. Instead of arranging the optical variablelayer 229, the protective layer 227 may play a role as the opticalvariable layer 229.

Second Embodiment

The second embodiment is related to, for example, the followingtechniques.

(1) An image display comprising a light-transmitting intermediate layerhaving first and second main surfaces, a first image-displaying portionthat is provided on the first main surface and displays firstinformation about a certain object as a first image of object color, anda second image-displaying portion that is provided on the second mainsurface and displays second information about the object as a secondimage of structural color provided by a relief structure.(2) The image display according to the item (1), wherein the object is aliving body, and each piece of the first and second information isbiometric information.(3) The image display according to the item (2), wherein the firstimage-displaying portion displays a facial image as the first image, andthe second image-displaying portion displays a facial image as thesecond image.(4) The image display according to item (2) or (3), wherein the livingbody is a person, and the image display is used for an individualauthentication.(5) The image display according to any one of the items (1) to (4),further comprising a third image-displaying portion that faces thesecond image-displaying portion with the intermediate layer interposedtherebetween and displays an image of self-luminous color whenilluminated with excitation light.(6) The image display according to any one of the items (1) to (4),further comprising a third image-displaying portion that is provided onthe first main surface, and is open in a shape corresponding to thesecond image-displaying portion at a position corresponding to thesecond image-displaying portion, wherein the third image-displayingportion displays a background of the second image as an image of objectcolor or displays the background of the second image as an image ofself-luminous color when illuminated with excitation light.(7) The image display according to any one of the items (1) to (6),further comprising a fourth image-displaying portion that is provided onthe second main surface, and is open in a shape corresponding to thefirst image-displaying portion at a position corresponding to the firstimage-displaying portion, wherein the fourth image-displaying portiondisplays a background of the first image as an image of structuralcolor.(8) The image display according to any one of the items (1) to (7),wherein the second image-displaying portion comprises a relief structurethat emits a diffracted light, and the diffracted light displays thesecond image.(9) The image display according to any one of the items (1) to (7),wherein the second image-displaying portion includes a relief structureemitting a scattered light, and the scattered light displays the secondimage.(10) The image display according to any one of the items (1) to (9),wherein the intermediate layer includes one or more items selected fromthe group consisting of hologram, diffraction grating, infraredabsorbing layer, fluorescence layer, and print pattern displaying objectcolor.(11) The image display according to any one of the items (1) to (10),further comprising a light-transmitting protective layer that faces theintermediate layer with the first or second image-displaying portioninterposed therebetween, wherein the protective layer includes one ormore items selected from the group consisting of hologram, diffractiongrating, infrared absorbing layer, fluorescence layer, and print patterndisplaying object color.(12) A labeled article comprising the image display according to any oneof the items (1) to (11), and a substrate supporting the image display.(13) The labeled article according to the item (12), wherein thesubstrate is a card substrate or a booklet.(14) A labeled article according to the item (12) or (13) used forindividual authentication.

The effects of the techniques according to the items (1) to (14) will beindividually described.

The image display according to the item (1) includes the firstimage-displaying portion. The first image-displaying portion displaysthe first information about the certain object as the first image ofobject color. The first image of object color can be perceived undernormal illumination conditions with excellent visibility.

This image display includes not only the first image-displaying portionbut also the second image-displaying portion. This secondimage-displaying portion displays the second image of structural colorprovided by the relief structure. When the relief structure is used, theimage can be displayed with a higher precision as compared with the casewhere pearl pigments are used. It is difficult to falsify or tamper withthe second image-displaying portion itself.

In addition, on this image display, the first and secondimage-displaying portions display the information about the same object.For this reason, in order to rewrite the information about this objectwith the information about another object, each of the first and secondimage-displaying portions has to be at least partially removed.

Further, in this image display, the intermediate layer is interposedbetween the first and second image-displaying portions. Therefore, forexample, in order to at least partially remove each of the first andsecond image-displaying portions from the front side or from the backside, the intermediate layer has to be at least partially removed. Thatis, when each pieces of the first and second information about the aboveobject recorded in this image display is rewritten with informationabout another object, it is necessary to, for example, remove one of thefirst and second image-displaying portions, subsequently, at leastpartially remove the intermediate layer to expose the other of the firstand second image-displaying portions, and thereafter remove thisportion. This kind of process is impossible or extremely difficult.Moreover, the image display body subjected to such process can bedistinguished relatively easily from the image display that is notsubjected to such process by observation with unaided eyes.

Therefore, the image display according to the item (1) displays ahigh-resolution image and is hard to tamper with the recorded image.

In the image display according to the item (2), each piece of the firstand second information is biometric information. The biometricinformation is unique to the individual body. Therefore, in order tofraudulently use this image display for another individual body, bothpieces of the first and second information have to be rewritten.Therefore, in this case, it is more difficult to fraudulently use theimage display as compared with the case where at least one piece of thefirst and second information is non-biometric information.

In the image display according to the item (3), the first and secondimage-displaying portions display the facial image. The facial image isone of the images most suitable for individual authentication withvisual check.

In the image display according to the item (4), the above living body isa person, and the image display is used for an individualauthentication. This kind of use is one of most useful applications ofthe image display.

The image display according to the item (5) further comprises a thirdimage-displaying portion that faces the second image-displaying portionwith the intermediate layer interposed therebetween and displays animage of self-luminous color when irradiated with excitation light.Under the illumination conditions of irradiating with the excitationlight, this image display displays an image that is different in atleast one of the color and the shape from the image obtained undernormal illumination conditions such as sunlight and indoor illuminationlight. That is, this image display gives more complicated visualeffects. Since the intermediate layer is interposed between the secondand third image-displaying portions, in order to rewrite the imagedisplayed by the second and third patterns, not only the second andthird patterns but also the intermediate layer needs to be removed atleast partially. In other words, it is more difficult to tamper with theinformation on this image display, and therefore, it is more difficultto fraudulently use the image display.

The image display according to the item (6) further comprises a thirdimage-displaying portion provided on the first main surface. The thirdimage-displaying portion is open in a shape corresponding to the secondimage-displaying portion at a position corresponding to the secondimage-displaying portion, and the third image-displaying portiondisplays a background of the second image as an image of object color,or displays the background of the second image as an image ofself-luminous color when irradiated with excitation light. In the caseof employing this configuration, when only the second image displayed bythe second image-displaying portion is counterfeited, the outline of thecounterfeit second image and the opening in the third image-displayingportion are likely to become inconsistent in terms of the shape or theposition. Therefore, the counterfeit information can be checked by usingthis.

The image display according to the item (7) further comprises a fourthimage-displaying portion provided on the second main surface. The fourthimage-displaying portion is open in a shape corresponding to the firstimage-displaying portion at a position corresponding to the firstimage-displaying portion, and the fourth image-displaying portiondisplays a background of the first image as an image of structuralcolor. In the case of employing this configuration, when only the firstimage displayed by the first image-displaying portion is counterfeited,the outline of the counterfeit first image and the openings arranged inthe fourth image-displaying portion are likely to become inconsistent interms of the shape or the position. Therefore, the counterfeitinformation can be checked by using this.

In the image display according to the item (8), the secondimage-displaying portion includes a relief structure that emits adiffracted light, and the diffracted light displays the second image.Therefore, the color of the second image changes according to theillumination direction, the observation direction, and the like. Inother words, when this configuration is employed, complicated visualeffects can be achieved.

In the image display according to the item (9), the secondimage-displaying portion includes a relief structure emitting ascattered light, and the scattered light displays the second image.Since the second image-displaying portion displays the second image withthe scattered light, even when this image display is adhered to, forexample, an uneven surface, the effect of this uneven surface on theimage quality of the second image is relatively small.

In the image display according to the item (10), the intermediate layerincludes one or more items selected from the group consisting ofhologram, diffraction grating, infrared absorbing layer, fluorescencelayer, and print pattern displaying object color. Such an image displayprovides more complicated visual effects, and in addition, is hard tocounterfeit or tamper with the information.

The image display according to the item (11) further comprises alight-transmitting protective layer that faces the intermediate layerwith the first or second image-displaying portion interposedtherebetween. In such an image display, the first and secondimage-displaying portions and the like are less prone to be damaged. Inaddition, this protective layer includes one or more items selected fromthe group consisting of hologram, diffraction grating, infraredabsorbing layer, fluorescence layer, and print pattern displaying objectcolor. This image display provides more complicated visual effects andis hard to counterfeit or tamper with the information.

The labeled article according to the item (12) includes the imagedisplay according to any one of the items (1) to (11). Therefore, thislabeled article displays a high-resolution image and is hard to tamperwith the image recorded thereon.

In the labeled article according to the item (13), the substrate is acard substrate or a booklet. Typically, the above-described labeledarticle is used in such forms.

The labeled article according to the item (14) is used for individualauthentication. This kind of use is one of most useful applications ofthe labeled article.

Subsequently, the second embodiment will be described with reference todrawings.

FIG. 14 is a plan view schematically showing a labeled article accordingto the second embodiment of the present invention.

The labeled article 100 shown in FIG. 14 is the same as the labeledarticle 100 described with reference to FIGS. 1 to 5 except that thefollowing features are different.

That is, in this labeled article 100, the cover sheet 2 displays notonly images I1 a, I1 b, and I2 but also images I3 c and I3 d.

At least a part of the image I3 c constitutes a background of the imageI1 a. The image I3 c is, for example, an image of object color or animage of structural color. Here, as an example, the image I3 c issupposed to be an image of structural color.

At least a part of the image I3 d constitutes a background of the imageI1 b. The image I3 d is, for example, an image of object color or animage of structural color. Here, as an example, the image I3 d isassumed to be an image of object color.

FIG. 15 is a cross sectional view schematically showing an example of astructure that can be employed in the labeled article shown in FIG. 14.FIG. 16 is an enlarged plan view of a part of the labeled article shownin FIG. 14. FIG. 17 is an enlarged plan view of another part of thelabeled article shown in FIG. 14. FIG. 18 is an enlarged cross sectionalview of a part of the labeled article shown in FIG. 14. FIG. 19 is anenlarged cross sectional view of another part of the labeled articleshown in FIG. 14.

It should be noted that FIG. 16 depicts a structure of a part of thecover sheet 2 that corresponds to the images I1 a and I3 c. It shouldalso be noted that FIG. 17 depicts a structure of a part of the coversheet 2 that corresponds to the images I1 b and I3 d. FIGS. 18 and 19depict a structure included in a part of the cover sheet 2 that displaysthe image I1 b and a structure included in a part of the cover sheet 2that displays the image I3 c, respectively.

The structure shown in FIGS. 15 to 19 is the same as the structuredescribed with reference to FIGS. 2 to 5 except that the followingfeatures are different.

That is, in this structure, the image display 22 includes not only theimage display layers 220 a and 220 b but also image display layers 220 cand 220 d. The image display layers 220 c and 220 d display the imagesI3 c and I3 d shown in FIG. 14, respectively. The image display 22 mayfurther include an image-displaying portion (not shown) displaying theimage I2 shown in FIG. 1.

As shown in FIG. 15, the image display layer 220 c is provided in aregion Ac that is juxtapose to regions Aa and Ab and adjacent to theregion Aa. The image display layer 220 c is open at a positioncorresponding to the image display layer 220 a in a shape correspondingto the image display layer 220 a. The image display layer 220 c displaysa background of an image displayed by the image display layer 220 a asan image of structural color, e.g., an image of structural colorprovided by the relief structure. Here, the image display layer 220 cdisplays the image I3 c shown in FIG. 14.

The image display layer 220 c is a layer including, for example, arelief structure formation layer 223 c, a reflection layer 224 c, and anadhesive layer 225 c as shown in FIG. 19. The reflection layer 224 c isinterposed between the relief structure formation layer 223 c and theadhesive layer 225 c. The image display layer 220 c is provided suchthat, for example, the relief structure formation layer 223 c and thereflection layer 224 c are interposed between the adhesive layer 225 cand the cover sheet main body 21.

The relief structure formation layer 223 c is a layer provided with arelief structure on a main surface thereof. This relief structureincludes, for example, at least one of diffraction grating and hologramas a diffraction structure. This relief structure displays the thirdimage I3 c of structural color described above.

The relief structure formation layer 223 c includes, for example, firstto third portions producing different colors when they are illuminatedwith white light in a particular illumination direction and observed ina particular observation direction. The first to third portions aredifferent from each other in at least one of the grating constant andthe lengthwise direction of the grooves of the diffraction grating.Under a particular observation condition, the first to third portionsproduce, for example, blue, green, and red colors, respectively.

The material of the relief structure formation layer 223 c may be, forexample, that mentioned for the relief structure formation layer 223 b.Typically, the relief structure formation layer 223 c obtained usingsuch transparent resin has a refractive index within a range of 1.3 to1.7 with respect to light having a wavelength of 550 nm.

The reflection layer 224 c is formed on the relief structure formationlayer 223 c. The reflection layer 224 c covers at least a part of thesurface of the relief structure formation layer 223 c on which therelief structure is provided. Although the reflection layer 224 c can beomitted, the visibility of the image displayed by the diffractionstructure can be improved when the reflection layer 224 c is provided.

The reflection layer 224 c may be, for example, that mentioned for thereflection layer 224 b. The reflection layer 224 c can be formed by, forexample, the method described for the reflection layer 224 b.

The adhesive layer 225 c is provided on the reflection layer 224 c. Theadhesive layer 225 c is made of, for example, thermoplastic resin. Thematerial of the adhesive layer 225 c may be, for example, that mentionedfor the adhesive layer 225 b.

The image display layer 220 c can be obtained by, for example, thermaltransfer recording method using a thermal head. In this case, the imagedisplay layer 220 c includes, for example, a plurality of dots arrangedtwo-dimensionally as shown in FIG. 16.

As shown in FIG. 15, the image display layer 220 d is provided in theregion Ab and a region Ad that is juxtapose to the regions Aa to Ac andadjacent to the region Ab. A part of the image display layer 220 d isinterposed between the image display layer 220 b and the cover sheetmain body 21. In the region Ad, the image display layer 220 d displaysthe background of the image displayed by the image display layer 220 bsuch as fine pattern as an image of object color. Here, the imagedisplay layer 220 d displays the image I3 d shown in FIG. 14. In theregion Ab, the image display layer 220 d displays, for example, the sameimage as that displayed by the image display layer 220 b. Alternatively,in the region Ab, the image display layer 220 d displays the imagedifferent from the image displayed by the image display layer 220 b suchas fine pattern.

The image display layer 220 d is, for example, a layer that contains atleast one of dye and pigment and optionally a resin. The image displaylayer 220 d can be obtained by, for example, thermal transfer recordingmethod using a thermal head, ink jet recording method,electrophotographic method, or a combination of two or more of them. Inthis case, the image display layer 220 d includes, for example, aplurality of dots arranged two-dimensionally as shown in FIG. 17.

The thicknesses of the image display layers 220 a to 220 d are within arange of, for example, 0.1 μm to 2.0 μm. The image display layers 220 ato 220 d may have the same thickness or different thicknesses. Each ofthe image display layers 220 a to 220 d may have uniform thickness ormay have uneven thickness.

In each of the image display layers 220 a to 220 d, the dots juxtaposedto each other may be away from each other, or may be in contact witheach other. In the latter case, the juxtaposed dots may partiallyoverlap each other. In this case, as shown in FIGS. 16 and 17, there maybe a gap enclosed by a plurality of dots, or such gap may not exist.

The image display layer 220 a may not be patterned. In other words, theimage display layer 220 a may be a continuous film. In this case, theimage display layer 220 a can be formed by forming a layer including aheat-sensitive color-producing agent and drawing on this layer withlaser beam.

As shown in FIG. 15, the image display 22 further includes anintermediate layer 229.

The intermediate layer 229 has first and second main surfaces. Here, thefirst main surface is a front surface, and the second main surface is aback surface facing the cover sheet main body 21. The image formationlayers 220 b and 220 c are located on the front side of the intermediatelayer 229. On the other hand, the image formation layers 220 a and 220 dare located on the backside of the intermediate layer 229.

The intermediate layer 229 has a light-transmitting property. Forexample, the intermediate layer 229 is a layer all of which istransparent or a portion thereof is transparent.

The intermediate layer 229 is made of, for example, a transparent resin.The material of the intermediate layer 229 may be, for example, a singleresin or a combination of resins such as polyacrylic ester thermoplasticresin, chlorinated rubber resin, vinyl chloride-vinyl acetate copolymerresin, cellulose resin, chlorinated polypropylene resin, epoxy resin,polyester resins, nitrocellulose resin, styrene acrylate resin,polyether resin, and polycarbonate resin. The intermediate layer 229 mayhave a single-layer structure or a multilayer structure.

The thickness of the intermediate layer 229 is, for example, within arange of 1 μm to 20 μm. In the case where the intermediate layer 229 isthin, when the protective layer 227 is partially removed to tamper withinformation, it may be impossible to notice this by observing the imagedisplay 22 with unaided eyes. On the other hand, in the case where theintermediate layer 229 is thick, when the commercially available film isattached to the removed portion, it may be impossible to notice, byobserving the image display 22 with unaided eyes, that the intermediatelayer 229 is partially replaced with the commercially available film.

The intermediate layer 229 may have in-plane uniformity of opticalproperty. Alternatively, the intermediate layer 229 may have in-planeunevenness of optical property.

The intermediate layer 229 may include one or more items selected fromthe group consisting of hologram, diffraction grating, infraredabsorbing layer, fluorescence layer, and print pattern providing objectcolor. When the intermediate layer 229 is partially removed, this can bereadily noticed. It should be noted that the infrared absorbing layerand the fluorescence layer may be a continuous film, or may be patternedin a grid shape, an island shape, or a stripe shape. In the latter case,the intermediate layer 229 employs, for example, a multilayer structureincluding a patterned infrared absorbing layer or fluorescence layer anda light-transmitting layer supporting this. Here, as an example, it issupposed that a relief-type hologram is provided on the entire surfaceof the intermediate layer 229.

The image display 22 includes the image display layer 220 a. The imagedisplay layer 220 a displays a facial image of a certain person as animage of object color. The facial image of object color can be observedunder normal illumination conditions with excellent visibility.

This image display 22 includes not only the image display layer 220 abut also the image display layer 220 b. The image display layer 220 bdisplays an image of structural color provided by the relief-typediffraction grating. When the relief structure is used, the image can bedisplayed with a higher precision as compared with the case where pearlpigments are used.

In this image display 22, the image display layers 220 a and 220 bdisplay the facial images of the same person. It is difficult to falsifyor tamper with the image display layer 220 b itself. Therefore, when thelabeled article 100 as a genuine article includes the image displaylayers 220 a and 220 b that display the facial images of the sameperson, more particularly, display the same facial image, genuineness ofan article whose genuineness is unknown can be checked by, for example,comparing two facial images displayed thereon.

The color of the image I1 b displayed by the image display layer 220 bchanges according to the illumination direction, the observationdirection, and the like. The image display layer 220 b can display, asthe image I1 b, a single color two-dimensional image, a multi-colortwo-dimensional image, a single color three-dimensional image, amulti-color three-dimensional image, or a combination of two or more ofthem. In other words, when this configuration is employed, complicatedvisual effects can be achieved.

In addition, in this image display 22, the image display layer 220 adisplays the image I1 a of object color, and the image display layer 220c displays the image I3 c of structural color as the background of theimage I1 a. Further, in this image display 22, the image display layer220 b displays the image I1 b of structural color, and the image displaylayer 220 d displays the image I3 d of object color as the background ofthe image I1 b. As described above, when one of the image of objectcolor and the image of structural color is adopted as the background ofthe other, more special visual effects can be achieved as compared withthe case where the image of object color is adopted as the background ofthe image of object color or the case where the image of structuralcolor is adopted as the background of the image of structural color. Forexample, when the image display layer 220 c displays a stereoscopicimage as the image I3 c, a quasi three-dimensional image can bedisplayed with the combination of the images I1 a and I3 c.

In this image display 22, the image display layer 220 d is provided notonly in the region Ad but also in the region Ab. In other words, a partof the image display layer 220 d faces the image display layer 220 b.Therefore, when the image display layer 220 b has a light-transmittingproperty, the image displayed by the image display layer 220 d in theregion Ab can be seen through the image display layer 220 b. In otherwords, this image display 22 displays the image of object color and theimage of structural color at the same time in the region Ab. That is,when this configuration is employed, more complicated visual effects canbe achieved.

The biometric information such as the facial image is unique to theindividual body. Therefore, in order to fraudulently use this imagedisplay 22 for another individual body, both of the images displayed bythe image display layers 220 a and 220 b have to be rewritten. That is,each of the image display layers 220 a and 220 b has to be at leastpartially removed. Therefore, in this case, it is more difficult tofraudulently use the image display 22 as compared with the case where atleast one of these images is non-biometric information.

Further, in this image display 22, the intermediate layer 229 isinterposed between the image display layers 220 a and 220 b. In thelabeled article 100 including the image display 22, the image display 22is supported by the cover sheet main body 21 such that the image displaylayer 220 a is interposed between the intermediate layer 229 and thecover sheet main body 21. Therefore, for example, in order to at leastpartially remove each of the image display layers 220 a and 220 b fromthe front side or the backside, the intermediate layer 229 has to be atleast partially removed. In other words, in order to write the facialimage recorded on the image display 22 with the facial image of anotherperson, for example, the following process is necessary. The imagedisplay 22 is released from the cover sheet main body 21, the imagedisplay layer 220 a is removed from the backside of the image display22, and subsequently, a part of the intermediate layer 229 is removed toexpose the image display layer 220 b, and thereafter, this is removed.Alternatively, the following process is necessary. The image displaylayer 220 b is removed from the front side of the image display 22, andsubsequently, a part of the intermediate layer 229 is removed to exposethe image display layer 220 a, and thereafter, this is removed. Thiskind of process is impossible or extremely difficult. Moreover, inparticular, when at least one of the protective layer 227 and theintermediate layer 229 includes one or more item selected from the groupconsisting of hologram, diffraction grating, infrared absorbing layer,fluorescence layer, and print pattern producing object color, the imagedisplay 22 subjected to such process can be distinguished relativelyeasily from an image display 22 that is not subjected to such process.

In this image display 22, the image display layer 220 c is open at aposition corresponding to the image display layer 220 a in a shapecorresponding to the image display layer 220 a, and displays thebackground of the image I1 a as the image I3 c of structural color. Inthe case of employing this configuration, when only the image I1 adisplayed by the image display layer 220 a is counterfeited, the outlineof the counterfeit image I1 a and the opening in the image display layer220 c are likely to become inconsistent in terms of the shape or theposition. Therefore, the counterfeit information can be checked by usingthis.

Therefore, it is difficult to tamper with the image recorded on theimage display 22. Thus, the labeled article 100 including the imagedisplay 22 is less likely to be fraudulently used.

The labeled article 100 can be modified in various forms.

FIG. 20 is a cross sectional view schematically showing another exampleof a structure that can be employed in the labeled article shown in FIG.14.

The labeled article 100 shown in FIG. 20 is the same as the labeledarticle 100 described with reference to FIGS. 14 to 19 except for thefollowing features.

The image display 22 of the labeled article 100 does not include theimage display layers 220 c and 220 d. The image display layer 220 a isprovided not only in the region Aa but also in the region Ac. The imagedisplay layer 220 b is provided not only in the region Ab but also in aregion Ad. In other words, the image display layer 220 a displays imagesI1 a and I3 c shown in FIG. 14 as images of object color. The imagedisplay layer 220 b displays images I1 b and I3 d shown in FIG. 14 asimages of structural color.

When this configuration is employed, the same effects as those obtainedfrom the configuration described with reference to FIGS. 14 to 19 can beobtained except that the effects associated with the image displaylayers 220 c and 220 d cannot be obtained.

Although the image display layer 220 a is provided not only in theregion Aa but also in the region Ac, the image display layer 220 a maynot be provided in the region Ac. In other words, the image I3 c shownin FIG. 14 may be omitted. Although the image display layer 220 b isprovided not only in the region Ab but also in the region Ad, the imagedisplay layer 220 b may not be provided in the region Ad. In otherwords, the image I3 d shown in FIG. 14 may be omitted.

FIG. 21 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14.

The labeled article 100 shown in FIG. 21 is the same as the labeledarticle 100 described with reference to FIGS. 14 to 19 except for thefollowing features.

The image display 22 of the labeled article 100 does not include theimage display layer 220 c. The image display layer 220 a is provided notonly in the region Aa but also in the region Ac. In other words, theimage display layer 220 a displays images I1 a and I3 c shown in FIG. 14as images of object color.

When this configuration is employed, the same effects as those obtainedfrom the configuration described with reference to FIGS. 14 to 19 can beobtained except that the effects associated with the image display layer220 c cannot be obtained.

FIG. 22 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14.

The labeled article 100 shown in FIG. 22 is the same as the labeledarticle 100 described with reference to FIGS. 14 to 19 except for thefollowing features.

The image display 22 of the labeled article 100 does not include theimage display layer 220 c. The image display layer 220 a is provided notonly in the region Aa but also in the region Ac. In other words, theimage display layer 220 a displays images I1 a and I3 c shown in FIG. 14as images of object color. The image display 22 of the labeled articleshown in FIG. 22 includes an image display layer 220 d′ producingself-luminous color instead of the image display layer 220 d producingobject color. The image display layer 220 d′ is a third image-displayingportion. The image display layer 220 d′ is made of, for example,fluorescent material or a mixture including fluorescent material andtransparent resin.

When this configuration is employed, the effects associated with theimage display layer 220 c cannot be obtained. When the image displaylayer 220 d′ is colorless and transparent, the effects associated withthe image display layer 220 d cannot be obtained. However, the imagedisplay layer 220 d′ displays the image in self-luminous color whenirradiated with excitation light such as ultraviolet light. When theimage display layer 220 d′ is, for example, colorless and transparent,the image display layer 220 d′ can be used as a latent image.

In other words, when the image display layer 220 d′ is colorless andtransparent, the same effects as those obtained from the configurationdescribed with reference to FIGS. 14 to 19 can be obtained except thatthe effects associated with the image display layers 220 c and 220 dcannot be obtained. In addition, in this case, the latent imagevisualized by irradiating with excitation light can be recorded usingthe image display layer 220 d′. Therefore, when this labeled article 100is a genuine article, genuineness of an article whose genuineness isunknown can be checked by, for example, irradiating with the excitationlight and observing the image produced by this article.

When the image display layer 220 d′ is colored and transparent,colorless and opaque, or colored and opaque, the same effects as thoseobtained from the configuration described with reference to FIGS. 14 to19 can be obtained except that the effects associated with the imagedisplay layer 220 c cannot be obtained. In addition, in this case, theimage display layer 220 d′ produces different colors when it isilluminated with natural light and excitation light. In other words,complicated visual effects are provided.

FIG. 23 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14.

The labeled article 100 shown in FIG. 23 is the same as the labeledarticle 100 described with reference to FIGS. 14 to 19 except for thefollowing features.

The image display 22 of the labeled article 100 does not include theimage display layer 220 c. The image display layer 220 a is provided notonly in the region Aa but also in the region Ac. In other words, theimage display layer 220 a displays images I1 a and I3 c shown in FIG. 14as images of object color. The image display layer 220 d is not providedin the region Ab, but is provided only in the region Ad.

When this configuration is employed, the same effects as those obtainedfrom the configuration described with reference to FIGS. 14 to 19 can beobtained except for the following features. That is, when thisconfiguration is employed, the effects associated with the image displaylayer 220 c cannot be obtained. Even if the image display layer 220 bhas a light-transmitting property, the image display layer 220 d cannotbe seen through the image display layer 220 b. However, in the case ofemploying this configuration, when the image I1 b displayed by the imagedisplay layer 220 b is counterfeited, the outline of the counterfeitimage I1 b and the openings arranged in the image display layer 220 dare likely to become inconsistent in terms of the shape or the position.Therefore, the counterfeit information can be checked by using this.

FIG. 24 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14.

The labeled article 100 shown in FIG. 24 is the same as the labeledarticle 100 described with reference to FIGS. 14 to 19 except for thefollowing features.

The image display 22 of the labeled article 100 does not include theimage display layer 220 d. The image display layer 220 b is provided notonly in the region Ab but also in the region Ad. In other words, theimage display layer 220 b displays images I1 b and I3 d shown in FIG. 14as images of structural color. The image display layer 220 c is providednot only in the region Ac but also in the region Aa. This image displaylayer 220 c has a light-transmitting property at least in the region Aa.As shown in FIG. 14, the image display layer 220 c displays the image I3c as the background of the image I1 a in the region Ab. In the regionAa, the image display layer 220 c displays, for example, the same imageas the image displayed by the image display layer 220 a. Alternatively,in the region Aa, the image display layer 220 c displays an imagedifferent from the image displayed by the image display layer 220 a suchas fine pattern.

When this configuration is employed, the same effects as those obtainedfrom the configuration described with reference to FIGS. 14 to 19 can beobtained except for the following features. In other words, when thisconfiguration is employed, the effects associated with the image displaylayer 220 d cannot be obtained. However, since a part of the imagedisplay layer 220 c faces the image display layer 220 a, the imagedisplayed by the image display layer 220 a in the region Aa can be seenthrough the image display layer 220 c. In other words, this imagedisplay 22 displays the image of object color and the image ofstructural color at the same time in the region Aa. Therefore, when thisconfiguration is employed, more complicated visual effects can beachieved.

FIG. 25 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14.

The labeled article 100 shown in FIG. 25 is the same as the labeledarticle 100 described with reference to FIGS. 14 to 19 except for thefollowing features.

The image display 22 of the labeled article 100 does not include theimage display layer 220 d. The image display layer 220 b is provided notonly in the region Ab but also in the region Ad. In other words, theimage display layer 220 b displays images I1 b and I3 d shown in FIG. 14as images of structural color.

When this configuration is employed, the same effects as those obtainedfrom the configuration described with reference to FIGS. 14 to 19 can beobtained except that the effects associated with the image display layer220 cannot be obtained.

According to the above configuration, the image display layers 220 a and220 b are arranged on the back and front sides of the intermediate layer229, respectively. As described below, the image display layers 220 aand 220 b can be arranged on the front and back sides of theintermediate layer 229, respectively.

FIG. 26 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14.

The labeled article 100 shown in FIG. 26 is the same as the labeledarticle 100 described with reference to FIGS. 14 to 19 except for thefollowing features.

The image display 22 of the labeled article 100 does not include theimage display layers 220 c and 220 d. The image display layer 220 a isinterposed between the intermediate layer 229 and the protective layer227, and is provided not only in the region Aa but also in the regionAc. The image display layer 220 b is interposed between the intermediatelayer 229 and the adhesive layer 225, and is provided not only in theregion Ab but also in the region Ad. In other words, the image displaylayer 220 a displays images I1 a and I3 c shown in FIG. 14 as images ofobject color. The image display layer 220 b displays images I1 b and I3d shown in FIG. 14 as images of structural color.

When this configuration is employed, the same effects as those obtainedfrom the configuration described with reference to FIGS. 14 to 19 can beobtained except that the effects associated with the image displaylayers 220 c and 220 d cannot be obtained.

FIG. 27 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14.

The labeled article 100 shown in FIG. 27 is the same as the labeledarticle 100 described with reference to FIGS. 14 to 19 except for thefollowing features.

The image display 22 of the labeled article 100 does not include theimage display layer 220 c. The image display layer 220 a is interposedbetween the intermediate layer 229 and the protective layer 227, and isprovided not only in the region Aa but also in the region Ac. In otherwords, the image display layer 220 a displays images I1 a and I3 c shownin FIG. 14 as images of object color. In addition, the image display 22includes the image display layer 220 d′ described with reference to FIG.22 instead of the image display layer 220 d. The image display layer 220d′ is interposed between the intermediate layer 229 and the protectivelayer 227. Further, in this image display 22, the image display layer220 d is interposed between the intermediate layer 229 and the adhesivelayer 225. The image display layer 220 d is not provided in the regionAb, but is provided only in the region Ad.

When this configuration is employed, the effects associated with theimage display layers 220 c and 220 d cannot be obtained. However, theimage display layer 220 d′ displays the image in self-luminous colorwhen irradiated with excitation light such as ultraviolet light. Whenthe image display layer 220 d′ is, for example, colorless andtransparent, the image display layer 220 d′ can be used as a latentimage.

In other words, when the image display layer 220 d′ is colorless andtransparent, the same effects as those obtained from the configurationdescribed with reference to FIGS. 14 to 19 can be obtained except thatthe effects associated with the image display layers 220 c and 220 dcannot be obtained. In addition, in this case, the latent imagevisualized by irradiating with excitation light can be recorded usingthe image display layer 220 d′. Therefore, when this labeled article 100is a genuine article, genuineness of an article whose genuineness isunknown can be checked by, for example, irradiating it with theexcitation light and observing the image produced by this article.

When the image display layer 220 d′ is colored and transparent,colorless and opaque, or colored and opaque, the same effects as thoseobtained from the configuration described with reference to FIGS. 14 to19 can be obtained except for the following features. That is, when thisconfiguration is employed, the effects associated with the image displaylayer 220 c cannot be obtained. Even if the image display layer 220 b′has a light-transmitting property, the image display layer 220 d′ cannotbe seen through the image display layer 220 b. However, in the case ofemploying this configuration, when the image I1 b displayed by the imagedisplay layer 220 b is counterfeited, the outline of the counterfeitimage I1 b and the openings arranged in the image display layer 220 d′are likely to become inconsistent in terms of the shape or the position.Therefore, the counterfeit information can be checked by using this.

FIG. 28 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14.

The labeled article 100 shown in FIG. 28 is the same as the labeledarticle 100 described with reference to FIGS. 14 to 19 except for thefollowing features.

In the image display 22 of the labeled article 100, the image displaylayer 220 a is interposed between the intermediate layer 229 and theprotective layer 227, and the image display layers 220 b and 220 c areinterposed between the intermediate layer 229 and the adhesive layer225. This image display 22 does not include the image display layer 220d. The image display layer 220 b is provided not only in the region Abbut also in the region Ad. In other words, the image display layer 220 bdisplays images I1 b and I3 d shown in FIG. 14 as an image of structuralcolor.

When this configuration is employed, the same effects as those obtainedfrom the configuration described with reference to FIGS. 14 to 19 can beobtained except that the effects associated with the image display layer220 cannot be obtained.

FIG. 29 is a cross sectional view schematically showing still anotherexample of a structure that can be employed in the labeled article shownin FIG. 14.

The labeled article 100 shown in FIG. 29 is the same as the labeledarticle 100 described with reference to FIGS. 14 to 19 except for thefollowing features.

In the image display 22 of the labeled article 100, the image displaylayers 220 a and 220 d are interposed between the intermediate layer 229and the protective layer 227, and the image display layer 220 b isinterposed between the intermediate layer 229 and the adhesive layer225. The image display 22 does not include the image display layer 220c. The image display layer 220 a is provided not only in the region Aabut also in the region Ac. In other words, the image display layer 220 adisplays images I1 a and I3 c shown in FIG. 14 as images of objectcolor. Further, the image display layer 220 d has a light-transmittingproperty, for example, at least in the region Ab. Alternatively, atleast in the region Ab, the image display layer 220 d is formed into apattern of a grid, island, or stripe shape.

When this configuration is employed, the same effects as those obtainedfrom the configuration described with reference to FIGS. 14 to 19 can beobtained except for the following features. That is, when thisconfiguration is employed, the effects associated with the image displaylayer 220 c cannot be obtained. However, since a part of the imagedisplay layer 220 d faces the image display layer 220 b, the imagedisplayed by the image display layer 220 b in the region Ab can be seenthrough the image display layer 220 d. In other words, this imagedisplay 22 displays the image of object color and the image ofstructural color at the same time in the region Ab. Therefore, when thisconfiguration is employed, more complicated visual effects can beachieved.

In the above configuration, each of the image display layers 220 b and220 c includes a relief-type diffraction grating. At least one of theimage display layers 220 b and 220 c may include relief-type holograminstead of relief-type diffraction grating. Alternatively, at least oneof the image display layers 220 b and 220 c may include not only therelief-type diffraction grating but also the relief-type hologram.Alternatively, at least one of the image display layers 220 b and 220 cmay include, instead of or in addition to the relief-type diffractiongrating, a relief-type light-scattering structure described below or acombination of this light-scattering structure and relief-type hologram.

FIG. 30 is a plan view schematically showing an example of a structurethat can be employed in an image-displaying portion producing structuralcolor using light scattering. FIG. 31 is a perspective viewschematically showing another example of a structure that can beemployed in an image-displaying portion producing structural color usinglight scattering. FIG. 32 is a perspective view schematically showingstill another example of a structure that can be employed in animage-displaying portion producing structural color using lightscattering.

In the structure shown in FIG. 30, a plurality of recessed portionsand/or protruding portions RP are provided on an interface IFperpendicular to the Z direction. Each of the recessed portions and/orprotruding portions RP has a shape extending in the X direction, and therecessed portions and/or protruding portions RP are arranged in the Ydirection. The recessed portions and/or protruding portions RP haveuneven lengths in the X direction, and the positions thereof in the Xdirection and the Y direction are also irregular.

When this structure is illuminated with, for example, white light, thestructure exhibits higher light-scattering performance within a planeperpendicular to the X direction, and exhibits lower light-scatteringperformance within a plane perpendicular to the Y direction. Therefore,this structure is suitable for a case where it is desired to limit theemission direction of the scattered light, i.e., a case whereanisotropic light-scattering property is desired.

In this structure, the anisotropic light-scattering property is changedby changing the arrangement of the recessed portions and/or protrudingportions RP. For example, when the density of the recessed portionsand/or protruding portions RP is increased in the Y direction, theanisotropic light-scattering property increases. On the other hand, whenthe length of the recessed portions and/or protruding portions RP isreduced or the uniformity in the lengthwise direction is reduced, theanisotropic light-scattering property decreases.

In FIG. 30, the lengthwise directions of the recessed portions and/orprotruding portions RP are parallel to the X direction. The lengthwisedirections of the recessed portions and/or protruding portions RP maycross the X direction. In FIG. 30, the lengthwise directions of therecessed portions and/or protruding portions RP are aligned in onedirection. As long as the above anisotropic light-scattering property isobtained, the lengthwise directions of the recessed portions and/orprotruding portions RP may not be aligned in one direction.

In the structure shown in FIG. 31, the recessed portions and/orprotruding portions RP are in a rectangular solid shape. Each of therecessed portions and/or protruding portions RP has a shape extending inthe X direction, and the recessed portions and/or protruding portions RPare arranged in the Y direction. The positions of the recessed portionsand/or protruding portions RP in the X direction and the Y direction areirregular, and the sizes thereof in the X direction and the Y directionare also irregular. In this manner, the anisotropic light-scatteringproperty can also be changed by changing the sizes of the recessedportions and/or protruding portions RP.

In the structure shown in FIG. 31, the recessed portions and/orprotruding portions RP are in an elliptic cylinder shape. Each of therecessed portions and/or protruding portions RP has a shape extending inthe X direction, and the recessed portions and/or protruding portions RPare arranged in the Y direction. The positions of the recessed portionsand/or protruding portions RP in the X direction and the Y direction areirregular, and the sizes thereof in the X direction and the Y directionare also irregular. In this manner, the anisotropic light-scatteringproperty can also be changed by changing the shapes of the recessedportions and/or protruding portions RP.

The light-scattering structure having the anisotropic light-scatteringproperty can be used for displaying, for example, a three-dimensionalimage. That is, pixels each including a right eye sub-pixel and a lefteye sub-pixel are arranged in a matrix form. Some of the right eyesub-pixels are provided with light-scattering structures for right eyein order to display a parallax image for right eye. On the other hand,some of the left eye sub-pixel are provided with light-scatteringstructures for left eye in order to display a parallax image for lefteye. The light-scattering structure for right eye and thelight-scattering structure for left eye are different in the lengthwisedirections of the recessed portions and/or protruding portions RP. Whenthis kind of configuration is employed, a three-dimensional image usingdiffuse light can be displayed under typical indoor diffuse lightillumination conditions.

At least one of the image display layers 220 b and 220 c may include therelief structure described below.

FIG. 33 is a perspective view schematically showing an example of astructure that can be employed in an image-displaying portion displayingdark color as structural color.

In the structure shown in FIG. 33, an interface IF is provided with aplurality of recessed portions and/or protruding portion RP arrangedtwo-dimensionally. In this example, the recessed portions and/orprotruding portions RP are arranged in the X direction and the Ydirection to form a lattice. The recessed portions and/or protrudingportions RP may be arranged in two directions crossing diagonally toform a lattice.

Each of the recessed portions and/or protruding portions RP has atapered shape. The tapered shape is, for example, a half-spindle shape,a cone or pyramidal shape such as circular cone and pyramid, or atruncated cone or pyramidal shape such as truncated circular cone andtruncated pyramid. The side surface of the protruding portion PR may beformed with only an inclined surface, or may be in a staircase pattern.The tapered shape is useful for reducing the optical reflectance of therelief structure shown in FIG. 33. The recessed portions and/orprotruding portions RP may not have a tapered shape.

The recessed portions and/or protruding portions RP forms diffractiongrating. The center-to-center distance of the recessed portions and/orprotruding portions RP is shorter than that of a grating constant of anordinary diffraction grating. The center-to-center distance of therecessed portions and/or protruding portions RP is, for example, 400 nmor less.

A ratio of the height or the depth of the recessed portions and/orprotruding portions RP with respect to the center-to-center distancethereof is, for example, ½ or more, and in a typical case, one or more.The larger this ratio is, the smaller the reflectance of the reliefstructure is.

Since this relief structure has low reflectance, the relief structureappears to be dark gray to black. In this relief structure, thecenter-to-center distance of the recessed portions and/or protrudingportions RP is small. Thus, the diffracted light with excellentvisibility is not emitted in the front direction, but is emitted onlywithin a limited angular range. In other words, this relief structureappears to be dark gray to black printed layer. Moreover, it isdifficult to notice that this relief structure can emit diffractedlight.

In the structure shown in FIG. 33, the recessed portions and/orprotruding portions RP are regularly arranged, but the recessed portionsand/or protruding portions RP may be arranged irregularly. Such reliefstructure does not emit any diffracted light, but appears to be darkgray to black printed layer.

Subsequently, a method of manufacturing the above labeled article 100will be described.

FIG. 34 is a view schematically showing an example of a manufacturingapparatus that can be used to manufacture the labeled article shown inFIG. 14.

The manufacturing apparatus 500 shown in FIG. 34 can be used tomanufacture, for example, the labeled article 100 that employs thestructure described with reference to FIG. 15.

When the labeled article 100 is manufactured, for example, first, animage pickup device is used to shoot a face of a person. Alternatively,a facial image is read from a photoprint. Thus, the image information isobtained as electronic information. This facial image is processed asnecessary.

Subsequently, using the manufacturing apparatus 500 shown in FIG. 34,the image display 22 shown in FIG. 15 is formed on an article 100′. Itshould be noted that the article 100′ is the labeled article 100 fromwhich the image display 22 is omitted. Here, it is a booklet main body.

When the image display 22 is formed using the manufacturing apparatus500 shown in FIG. 34, thermal transfer ribbons 520 ac, 520 bc, 527, and529 are prepared.

The thermal transfer ribbon 520 ad is wound into a roll 540 b. Thethermal transfer ribbon 520 ad includes a belt-shaped first support bodyand a first transfer material layer formed thereon. The first transfermaterial layer is releasably supported by the first support body. A partof the first transfer material layer is used as the image formationlayer 220 a, and another part of the first transfer material layer isused as the image formation layer 220 d.

The thermal transfer ribbon 520 bc is wound into a roll 540 d. Thethermal transfer ribbon 520 bc includes a belt-shaped second supportbody and a second transfer material layer formed thereon. The secondtransfer material layer is releasably supported by the second supportbody. A part of the second transfer material layer is used as the imageformation layer 220 b, and another part of the second transfer materiallayer is used as the image formation layer 220 c.

The thermal transfer ribbon 527 is wound into a roll 540 c. The thermaltransfer ribbon 527 includes a belt-shaped third support body and athird transfer material layer formed thereon. The third transfermaterial layer is releasably supported by the third support body. A partof the third transfer material layer is used as the protective layer227.

The thermal transfer ribbon 529 is wound into a roll 540 a. The thermaltransfer ribbon 529 includes a belt-shaped fourth support body and afourth transfer material layer formed thereon. The fourth transfermaterial layer is releasably supported by the fourth support body. Apart of the fourth transfer material layer is used as the intermediatelayer 229.

After the above thermal transfer ribbons 520 ac, 520 bc, 527, and 529are prepared, the thermal transfer ribbons 529 and 520 ad are fed fromthe rolls 540 a and 540 b, respectively, and these are conveyed to athermal transfer printing device 550 a such that transfer materiallayers thereof face each other. In the thermal transfer printing device550 a, parts of the first transfer material layer of the thermaltransfer ribbon 520 ad are thermally transferred as the image displaylayers 220 a and 220 d from the first support body onto the fourthtransfer material layer of the thermal transfer ribbon 529.

The thermal transfer ribbon 520 ad used for this thermal transfer iswound into the roll 570 a. On the other hand, the thermal transferribbon 529 having the image display layers 220 a and 220 d formedthereon is guided by a guide roller 580 a and is conveyed to a thermaltransfer device 560 a together with the article 100′.

In the thermal transfer device 560 a, a part of the fourth transfermaterial layer of the thermal transfer ribbon 529 is thermallytransferred together with the image display layers 220 a and 220 d fromthe fourth support body onto the cover sheet main body 12 of the article100′. As a result, the image display layers 220 a and 220 d and theintermediate layer 229 are formed on the cover sheet main body 21.

It should be noted that this thermal transfer may be performed with theadhesive layer 225 interposed between thermal transfer ribbon 529 andthe cover sheet main body 12. For example, it is possible that theadhesive layer 225 is formed on at least one of the thermal transferribbon 529 and the cover sheet main body 21, and thereafter, thermaltransfer is performed.

The thermal transfer ribbon 529 used for this thermal transfer is guidedby guide rollers 580 b and 580 c, and then wound into the roll 570 a. Onthe other hand, the article 100′ having been subjected to this thermaltransfer process is conveyed to a thermal transfer device 560 b.

In parallel to the above operation, the thermal transfer ribbons 527 and520 bc are respectively fed from rolls 540 c and 540 d, and these areconveyed to a thermal transfer printing device 550 b such that transfermaterial layers thereof face each other. In the thermal transferprinting device 550 b, parts of the second transfer material layer ofthe thermal transfer ribbon 520 bc are thermally transferred as theimage display layers 220 b and 220 c from the second support body ontothe third transfer material layer of the thermal transfer ribbon 527.

The thermal transfer ribbon 520 bc used for this thermal transfer iswound into the roll 570 c. On the other hand, the thermal transferribbon 527 having the image display layers 220 b and 220 c formedthereon is guided by a guide roller 580 d, and is conveyed to a thermaltransfer device 560 b together with the article 100′ fed from a thermaltransfer device 560.

In the thermal transfer device 560 b, a part of the third transfermaterial layer of the thermal transfer ribbon 527 is transferredtogether with the image display layers 220 b and 220 c from the thirdsupport body onto the intermediate layer 229 provided on the cover sheetmain body 12 of the article 100′. As a result, the image display layers220 b and 220 c and the protective layer 227 are formed on theintermediate layer 229.

It should be noted that this thermal transfer may be performed with theadhesive layer interposed between the thermal transfer ribbon 527 andthe intermediate layer 229. For example, it is possible that theadhesive layer is formed on at least one of the thermal transfer ribbon527 and the intermediate layer 229, and thereafter, thermal transfer isperformed.

The thermal transfer ribbon 527 used for this thermal transfer is guidedby a guide roller 580 f, and is wound into the roll 570 b. Then, thearticle 100′ having been subjected to this thermal transfer process isdischarged from a thermal transfer device 560 b as the labeled article100.

Thus, the labeled article 100 is completed.

It should be noted that the labeled article 100 described with referenceto FIGS. 20, 21, 23 to 25 can be manufactured according to the abovemethod from which formation of one or both of the image display layers220 c and 220 d is omitted. The labeled article 100 described withreference to FIG. 22 can be manufactured according to the above methodfrom which formation of the image display layers 220 c and 220 d isomitted and to which a step of forming the image display layer 220 d′ isadded. The labeled article 100 described with reference to FIGS. 26, 28and 29 can be manufactured according to the above method in whichthermal transfer ribbons 520 ad and 520 cd are respectively wound intothe rolls 540 d and 540 b and from which formation of one or both of theimage display layers 220 c and 220 d is omitted. The labeled article 100described with reference to FIG. 27 can be manufactured according to theabove method in which the thermal transfer ribbons 520 ad and 520 cd arerespectively wound into the rolls 540 d and 540 b, from which formationof the image display layers 220 c and 220 d is omitted, and to which astep of forming the image display layer 220 d′ is added.

In the above method, thermal transfer is used to form the image displaylayers 220 b and 220 c, but the image display layers 220 b and 220 c maybe formed by other methods. For example, a light-transmitting layerhaving a main surface provided with a relief structure causingdiffraction or scattering is formed in advance on the protective layer227. Subsequently, the diffraction performance or scattering performanceof this relief structure is partially eliminated or partially reduced.For example, a part of the relief structure is destroyed by irradiatingan energy beam such as a laser beam. Alternatively, a material havingsubstantially the same refractive index as the light-transmitting layersuch as colorless resin (in a typical case, colorless and transparentresin) is supplied by print process such as ink jet printing onto a partof the relief structure, so that a pattern having a smooth surface isformed. Alternatively, a solvent is supplied by print process such asink jet printing onto a part of the relief structure, so that thesurface of the light-transmitting layer is melted in this portion.Thereafter, as necessary, the reflection layer is formed on the reliefstructure. For example, the reflection layer is formed by dry coatingsuch as vacuum evaporation and sputtering. Alternatively, the reflectionlayer is formed by applying light reflective material such as a mixtureof metal particles and transparent resin to the relief structure. Asdescribed above, the image display layers 220 b and 220 c are obtained.

The image display layers 220 b and 220 c may be formed according to thefollowing method. That is, a light-transmitting layer having a mainsurface provided with a relief structure causing diffraction orscattering is formed in advance on the protective layer 227. Then, alight reflective material is supplied by print process such as ink jetprinting onto a part of the relief structure. As a result, a lightreflection pattern is obtained as the reflection layer. Portionscorresponding to the light reflection pattern have higher diffractionperformance or scattering performance than portions corresponding toopenings of the light reflection pattern. Therefore, the image displaylayers 220 b and 220 c can also be obtained by such method.

In the above method, thermal transfer is used to form the image displaylayers 220 a and 220 d, but the image display layers 220 a and 220 d maybe formed by other methods. For example, the image display layers 220 aand 220 d may be formed by print process such as ink jet printing.

In the method described with reference to FIG. 34, thermal transfer tothe article 100′ is performed twice. However, the labeled article 100can be manufactured by performing thermal transfer to the article 100′only once.

FIG. 35 is a view schematically showing an example of a transfer foilthat can be used for manufacturing the labeled article shown in FIG. 14.

The transfer foil 203 shown in FIG. 35 includes a transfer materiallayer 22′ and a support body 226 releasably supporting the transfermaterial layer 22′.

The support body 226 is, for example, a resin film or sheet. The supportbody 226 is made of, for example, a heat-resistant material such aspolyethylene terephthalate (PET). A main surface of the support body 226supporting the transfer material layer 22′ may be provided with, forexample, a release layer containing fluorine resin or silicone resin.

The transfer material layer 22′ includes the protective layer 227, theintermediate layer 229, the adhesive layer 225, and the image formationlayers 220 a to 220 d. The protective layer 227, the intermediate layer229, and the adhesive layer 225 are stacked in this order from the sideof the support body 226. The image formation layers 220 a and 220 d areinterposed between the intermediate layer 229 and the adhesive layer225. The image formation layers 220 b and 220 c are interposed betweenthe intermediate layer 229 and the protective layer 227.

The transfer material layer 22′ is entirely or partially used formanufacturing the labeled article 100. The transfer material layer 22′or a part thereof is the same as the image display 22 shown in FIG. 15.

When the labeled article 100 is manufactured, for example, first, animage pickup device is used to shoot a face of a person. Alternatively,a facial image is read from a photoprint. Thus, the image information isobtained as electronic information. This facial image is processed asnecessary. Using this image information, the transfer material layer 22′is formed on the support body 226. Subsequently, at least a part of thetransfer material layer 22′ is thermally transferred from the supportbody 226 to the article 100′. As described above, the labeled article100 is obtained.

Third Embodiment

The third embodiment is related to, for example, the followingtechniques.

(1) An image display transferred from a support body to a substrate,comprising an underlayer releasably supported by the support body andhaving a light-transmitting property, a first image-displaying portionfacing the underlayer and displaying first information about a certainobject as a first image of object color, and a second image-displayingportion transferred onto the underlayer by thermal transfer using athermal head, wherein the second image-displaying portion displayssecond information about the object as a second image of structuralcolor provided by a relief structure when observed with unaided eyes anddisplays a microscopic image when observed under magnification, themicroscopic image being impossible or difficult to visually recognizewhen observed with unaided eyes.(2) The image display according to the item (1), wherein the secondimage-displaying portion displays a plurality of microscopic images whenobserved under magnification, the second image-displaying portionincludes dot-shaped portions, the center of each of the dot-shapedportions is located on a lattice point of a virtual planar lattice, andthe microscopic images are displayed with a pitch of an integralmultiple of the pitch of the arrangement of the dot-shaped portions suchthat each of the microscopic images is located within a region enclosedby an outline of the dot-shaped portion.(3) The image display according to the item (1) or (2), wherein themicroscopic image includes at least one of character and symbol.(4) The image display according to any one of the items (1) to (3),wherein the size of the character or the symbol is within a range of 1μm to 300 μm.(5) The image display according to any one of the items (1) to (4),wherein the object is a person.(6) The image display according to any one of the items (1) to (5),wherein the first and second images includes the same facial image.(7) An image display transferred from a support body to a substrate,comprising an underlayer releasably supported by the support body andhaving a light-transmitting property, a first image-displaying portionfacing the underlayer and displaying first information about a certainobject as a first image of object color, and a second image-displayingportion transferred onto the underlayer by thermal transfer using athermal head and including first and second relief structures, whereinthe first relief structure displays a first sub-image of structuralcolor when observed in a first direction under particular illuminationconditions, and when observed in a second direction different from thefirst direction under the illumination conditions, the first reliefstructure does not display the first sub-image or displays the firstsub-image darker as compared with the case where observed in the firstdirection, wherein the second relief structure displays a secondsub-image of structural color when observed in the second directionunder the illumination conditions, and when observed in the firstdirection under the illumination conditions, the second relief structuredoes not display the second sub-image or displays the second sub-imagedarker as compared with the case where observed in the second direction,and wherein the first sub-image includes a facial image, and the secondsub-image includes at least one of character and symbol.(8) The image display according to the item (7), wherein the secondimage-displaying portion includes dot-shaped portions, and the center ofeach of the dot-shaped portions is located on a lattice point of avirtual planar lattice.(9) The image display according to the item (7) or (8), wherein thefirst image and the first sub-image include the same facial image.(10) The image display according to any one of the items (1) to (9),further comprising an adhesive layer that faces the underlayer with thefirst image display layer interposed therebetween.(11) A labeled article comprising the image display according to any oneof the items (1) to (10), and a substrate onto which the image displayis transferred from the support body.(12) A primary transfer foil used for manufacturing the image displayaccording to the item (1), comprising a first support body, and a firsttransfer material layer releasably supported by the first support body,wherein the first transfer material layer includes a relief structuredisplaying an image of structural color and a plurality of patterns eachdisplaying a microscopic image, the microscopic image cannot be visuallyrecognized or is difficult to be visually recognized when observed withunaided eyes but can be visually recognized when observed undermagnification.

The effects of the techniques according to the items (1) to (12) will beindividually described.

The image display according to the item (1) is an image displaytransferred from a support body to a substrate, comprising an underlayerreleasably supported by the support body, and a second image-displayingportion transferred onto the underlayer by thermal transfer using athermal head. When the second image-displaying portion is directlyformed on the substrate of the labeled article by thermal transfer usinga thermal head, it is difficult to achieve high image quality due toroughness of the surface of the substrate. In contrast, in this imagedisplay, the second image display layer is not formed on the substrateof the labeled article, but is formed on the underlayer. This secondimage-displaying portion is transferred onto the substrate of thelabeled article together with the underlayer. Thus, the image quality isnot greatly affected by the surface roughness of the substrate and thelike. Therefore, when this image display is used, the labeled articledisplaying high quality image can be obtained.

This image display further comprises a first image-displaying portionfacing the underlayer and displaying first information about a certainobject as a first image of object color. The first image provides bettervisibility than the second image. Therefore, when the first and secondimage-displaying portions are used together, the image display candisplay the image with excellent visibility and the image having specialvisual effects.

The second image-displaying portion of the image display displays amicroscopic image when observed under magnification that cannot bevisually recognized or is difficult to be visually recognized whenobserved with unaided eyes. This process for recording the microscopicimages requires high accuracy. Therefore, it is difficult to tamper withthe information on this image display. The second image-displayingportion of this image display displays second information about theobject as a second image of structural color provided by a reliefstructure when observed with unaided eyes. It is extremely difficult totamper with the information displayed as the image of structural color.Further, this image display is adhered to the substrate of the labeledarticle by thermal transfer. The image display thus adhered to thesubstrate is easily destroyed when it is released from the substrate.Therefore, when this image display is used, the labeled article that isdifficult to be tampered with can be obtained.

In the image display according to the item (2), a plurality ofmicroscopic images are displayed by the second image-displaying portionwhen the second image-displaying portion is observed undermagnification. The second image-displaying portion includes a pluralityof dot-shaped portions. The center of each of these dot-shaped portionsis located on a lattice point of a virtual planar lattice. Thesemicroscopic images are displayed with a pitch of an integral multiple ofthe pitch of the arrangement of the dot-shaped portions such that eachof the microscopic images is located within a region enclosed by anoutline of the dot-shaped portion. This configuration is suitable forthe process for recording an image by thermal transfer using a thermalhead.

In the image display according to the item (3), the microscopic imageincludes at least one of character and symbol. For example, in the casewhere the labeled article is a passport, when the microscopic imageincludes a character string or symbol that indicates an issuing country,an authenticity check can be made on a passport whose authenticity isunknown by confirming this microscopic image. In the case where thelabeled article is an ID card, when the microscopic image includes acharacter string or symbol indicating an affiliation, an authenticitycheck can be made on an ID card whose authenticity is unknown byconfirming this microscopic image.

In the image display according to the item (4), the size of thecharacter or the symbol is within a range of 1 μm to 300 μm. In general,when the size of the characters or symbols is 300 μm or less, it isimpossible to discriminate the characters or symbols with unaided eyes.In general, when the size of the characters or symbols is 1 μm or more,the characters or symbols can be discriminated by observing thecharacters or symbols under magnification using, for example, amagnifying glass or an optical microscope. In particular, in order tomanufacture the structure displaying the characters or symbols whosesize is within the range of 1 μm to 50 μm with high precision, a highlevel of technology is required. Therefore, it is difficult tocounterfeit the image display, and it is difficult to tamper withinformation.

In the image display according to the item (5), the object is a person.In other words, the first and second information include personalinformation of the same person. In this case, it is more difficult tocounterfeit the image display, and in addition, the image display can beused for individual authentication.

In the image display according to the item (6), the first and secondimages include the same facial image. The facial image is suitable forindividual authentication. Further, the image display can be verifiedby, for example, comparing the first and second images.

Like the image display according to the item (1), the image displayaccording to the item (7) comprises an underlayer releasably supportedby the support body and a second image-displaying portion transferredonto the underlayer by thermal transfer using a thermal head. Therefore,when this image display is used, the labeled article displaying a highquality image can be obtained.

Like the image display according to the item (1), this image displayfurther comprises a first image-displaying portion. Therefore, thisimage display can display the image with excellent visibility and theimage having special visual effects.

Further, the second image-displaying portion includes first and secondrelief structures. The first relief structure displays a first sub-imageof structural color when observed in a first direction under particularillumination conditions, and when observed in a second directiondifferent from the first direction under the illumination conditions,the first relief structure does not display the first sub-image ordisplays the first sub-image darker as compared with the case whereobserved in the first direction. On the other hand, the second reliefstructure displays a second sub-image of structural color when observedin the second direction under the illumination conditions, and whenobserved in the first direction under the illumination conditions, thesecond relief structure does not display the second sub-image ordisplays the second sub-image darker as compared with the case whereobserved in the second direction. Therefore, when the observationdirection is changed, the image displayed by the second image-displayingportion changes between the first and second sub-images. That is, thisimage display provides more complicated visual effects.

The process for recording the image causing the above change requires ahigh level of technology, and it is extremely difficult to tamper withsuch image. Further, this image display is easily destroyed when it isreleased from the substrate, like the image display according to theitem (1). Therefore, when this image display is used, the labeledarticle that is difficult to be tampered with can be obtained.

In addition, in this image display, the first sub-image includes afacial image, and the second sub-image includes at least one ofcharacter and symbol. The facial image is suitable for individualauthentication. In the case where the labeled article is, for example, apassport, when the second sub-image includes a character string orsymbol that indicates the issuing country, an authenticity check can bemade on a passport whose authenticity is unknown by confirming thesecond sub-image. In the case where the labeled article is an ID card,when the second-image includes a character string or symbol indicatingan affiliation, an authenticity check can be made on an ID card whoseauthenticity is unknown by confirming the microscopic image.

In the image display according to the item (8), the secondimage-displaying portion includes a plurality of dot-shaped portions,and each of the centers of these dot-shaped portions is located on alattice point of a virtual planar lattice. This configuration issuitable for the process for recording an image by thermal transferusing a thermal head.

In the image display according to the item (9), the first image and thefirst sub-image include the same facial image. The facial image issuitable for individual authentication. Further, the image display canbe verified by, for example, comparing the first image and the firstsub-image.

The image display according to the item (10) further comprises anadhesive layer that faces the underlayer with the first image displaylayer interposed therebetween. When the image display is transferredfrom the support body to the labeled article, the adhesive layerstrongly bonds the image display with the substrate. In addition, theadhesive layer makes it difficult to replicate the relief structure.

The labeled article according to the item (11) includes the imagedisplay according to any one of the items (1) to (10) and a substrateonto which the image display is transferred from the support body.Therefore, in the labeled article, a high quality image is displayed bythe image display, and in addition, it is difficult to tamper with theinformation recorded on the image display.

The primary transfer foil according to the item (12) is used tomanufacture the image display according to the item (1). In this primarytransfer foil, the first transfer material layer includes a reliefstructure displaying an image of structural color and a plurality ofpatterns each displaying a microscopic image. The microscopic imagecannot be visually recognized or is difficult to be visually recognizedwhen observed with unaided eyes but can be visually recognized whenobserved under magnification. When this primary transfer foil is used,for example, an image formation body can be manufactured according tothe following method.

First, a structure including the second support body and the underlayerreleasably supported thereby and having a light-transmitting property isprepared. Subsequently, the first and second image-displaying portionsare formed on the underlayer. The first image-displaying portion isformed by, for example, printing or transferring process. On the otherhand, the second image-displaying portion is formed by thermallytransferring a part of the first transfer material layer from the firstsupport body onto the underlayer using a thermal head. In this manner,the second transfer material layer is formed on the underlayer.Thereafter, as necessary, the adhesive layer is formed on the secondtransfer material layer. As described above, the image display accordingto the item (1) is obtained.

Subsequently, the third embodiment will be described with reference todrawings.

FIG. 36 is a plan view schematically showing an individualauthentication medium according to the third embodiment of the presentinvention.

The labeled article 100 shown in FIG. 36 is the same as the labeledarticle 100 described with reference to FIGS. 1 to 5 except that thefollowing features are different.

In other words, in this labeled article 100, a cover sheet 2 displaysnot only images I1 a, I1 b and I2 but also an image I3.

The image I3 is ground tints. The image I3 is an image of object color.For example, combining the image I3 with at least one of the images I1 aand I1 b makes it more difficult to tamper with information recorded onthe labeled article 100. The image I3 may be omitted.

The image I3 is constituted by, for example, dye or pigments. In thiscase, the image I3 is formed by thermal transfer recording method usinga thermal head, ink jet recording method, electrophotographic method, ora combination of two or more of them. Alternatively, the image I3 can beformed by forming a layer including a heat-sensitive color-producingagent and drawing on this layer with laser beam. Alternatively, acombination of these methods may be used. At least a part of the imageI3 may be formed by thermal transfer recording method using a hot stamp,may be formed by printing method, or may be formed using a combinationof them.

FIG. 37 is an enlarged plan view showing a part of the image displayincluded in the labeled article of FIG. 36. FIG. 38 is a cross sectionalview taken along the line XXXVIII-XXXVIII of the image display shown inFIG. 37. FIG. 39 is an enlarged plan view showing another part of theimage display included in the labeled article shown in FIG. 36. FIG. 40is a cross sectional view taken along the line LX-LX of the imagedisplay shown in FIG. 39.

The structure shown in FIGS. 37 and 38 is a part of the cover sheet 2corresponding to the image I1 a. On the other hand, the structure shownin FIGS. 39 and 40 is a part of the cover sheet 2 corresponding to theimage I1 b. In FIGS. 38 and 40, the adhesive layer 225 described withreference to FIG. 2 is omitted.

The structure shown in FIGS. 37 to 40 is the same as the structuredescribed with reference to FIGS. 2 to 5 except that the followingfeatures are different.

That is, as shown in FIG. 39, in this structure, the dot-shaped portionsof the image display layer 220 b that constitute the pixels orsub-pixels of the image Ib display microscopic images I4. Themicroscopic image I4 is impossible or difficult to visually recognizewhen observed with unaided eyes and can be visually recognized whenobserved under magnification.

Typically, the microscopic image I4 includes at least one of characterand symbol. Here, the microscopic image I4 is the character string“TOP”.

In the case where the labeled article 100 is a passport, the microscopicimage I4 may include a character string or symbol indicating an issuingcountry. In this case, an authenticity check can be made on a passportwhose authenticity is unknown by confirming the microscopic image I4. Inthe case where the labeled article is an ID card, the microscopic imagemay include a character string or symbol indicating an affiliation. Inthis case, an authenticity check can be made on an ID card whoseauthenticity is unknown by confirming the microscopic image I4.

The size of the character or symbol is within a range of, for example, 1μm to 300 μm. In general, when the size of the characters or symbols is300 μm or less, it is not impossible to discriminate the characters orsymbols with unaided eyes. In general, when the size of the charactersor symbols is 1 μm or more, the characters or symbols can bediscriminated by observing the characters or symbols under magnificationusing, for example, a magnifying glass or an optical microscope. Inparticular, in order to manufacture the structure displaying thecharacters or symbols whose size is within the range of 1 μm to 50 μmwith high precision, a high level of technology is required. Therefore,it is difficult to counterfeit the image display, and it is difficult totamper with information.

The microscopic images I4 are arranged with a pitch of an integralmultiple of the pitch of the arrangement of the dot-shaped portionsconstituting the image display layer 220 b. In this case, themicroscopic images I4 are arranged with the same pitch as the pitch ofthe arrangement of the dot-shaped portions. The pitch of the arrangementof the microscopic images I4 may not be an integral multiple of thepitch of the arrangement of the dot-shaped portions constituting theimage display layer 220 b.

It should be noted that the image display layer 220 a shown in FIGS. 37and 38 are patterned. However, the image display layer 220 a may not bepatterned. In other words, the image display layer 220 a may be acontinuous film. In this case, the image display layer 220 a can beformed by forming a layer including a heat-sensitive color-producingagent and drawing on this layer with laser beam.

Subsequently, a manufacturing method for manufacturing the labeledarticle and the structure of the image display layer 220 b according tothe third embodiment will be described with reference to FIGS. 41 to 44.

FIG. 41 is a cross sectional view schematically showing an example of aprimary transfer foil that can be used for manufacturing the labeledarticle shown in FIGS. 36 to 40. FIG. 42 is a plan view schematicallyshowing an example of a structure that can be employed in the primarytransfer foil shown in FIG. 41. FIG. 43 is a cross sectional viewschematically showing an example of a secondary transfer foil that canbe manufactured using the primary transfer foil shown in FIG. 41. FIG.44 is a cross sectional view schematically showing an example of a usedprimary transfer foil.

The primary transfer foil 201 shown in FIGS. 41 and 42 is, for example,a transfer ribbon. As shown in FIG. 41, the transfer foil 201 includes asupport body 221 and a transfer material layer 220 b releasablysupported by the support body 221.

The support body 221 is, for example, a resin film or sheet. The supportbody 221 is made of, for example, a material having heat-resistantproperty such as polyethylene terephthalate. A main surface of thesupport body 221 supporting the transfer material layer 220 b may beprovided with, for example, a release layer containing fluorine resin orsilicone resin.

The transfer material layer 220 b includes a release layer 222 b, arelief structure formation layer 223 b, a reflection layer 224 b, and anadhesive layer 225 b. A part of the transfer material layer 220 b isused as the image display layer 220 b shown in FIGS. 39 and 40.

The release layer 222 b is formed on the support body 221. The releaselayer 222 b plays a role of stabilizing the release of the transfermaterial layer 220 b from the support body 221 as well as a role ofpromoting the adhesion of the image display layer 220 b to the coversheet main body 21. The release layer 222 b has a light-transmittingproperty, and is transparent in a typical case. The release layer 222 bis made of, for example, thermoplastic resin. The release layer 222 bmay be omitted.

The relief structure formation layer 223 b, the reflection layer 224 b,and the adhesive layer 225 b are formed in this order on the releaselayer 222 b. The relief structure formation layer 223 b, the reflectionlayer 224 b, and the adhesive layer 225 b are the same as thosedescribed with reference to FIG. 5. Here, as an example, the reliefstructure formation layer 223 b is assumed to be a transparent layerhaving a relief structure arranged on the surface thereof as adiffraction structure.

The microscopic images I4 shown in FIG. 42 is recorded on the transfermaterial layer 220 b. When the diffraction structure is formed on thesurface of the relief structure formation layer 223 b, the microscopicimages I4 can be recorded by, for example, forming different diffractionstructures in the region corresponding to the microscopic image I4 andin the other region. For example, when the diffraction grating isformed, the microscopic images I4 can be recorded by changing one ormore of lengthwise direction, pitch, and depth of the groove among theseregions. Alternatively, the microscopic images I4 may be recorded by,for example, forming the diffraction structure in only one of theregions corresponding to the microscopic images I4 and the otherregions. In this case, the region in which no diffraction structure isformed may be flat, or may be formed with light-scattering structure.

The microscopic image I4 may be recorded by forming a print pattern.This print pattern is provided, for example, between the reflectionlayer 223 b and the adhesive layer 225 b or on the adhesive layer 225 b.Alternatively, when the reflection layer 223 b has a light-transmittingproperty, this print pattern may be provided between the release layer222 b and the relief structure formation layer 223 b or between therelief structure formation layer 223 b and the reflection layer 224.

When the labeled article 100 is manufactured, for example, first, animage pickup device is used to shoot a face of a person. Alternatively,a facial image is read from a photoprint. Thus, the image information isobtained as electronic information. This facial image is processed asnecessary.

Subsequently, the laminated body 202 shown in FIG. 43 is prepared. Thislaminated body 202 is a layer having a multilayer structure, andincludes a support body 226 and also includes a release protective layer227 and a resin layer 228 formed thereon in this order. The multilayerstructure formed on the support body 226 constitutes an underlayer. Thesupport body 226 releasably supports this underlayer.

The support body 226 may be, for example, those mentioned for thesupport body 221.

The release protective layer 227 plays a role of stabilizing the releaseof the transfer material layer 22′, which includes the releaseprotective layer 227, the resin layer 228, and the image display layer220 b, from the support body 226 and a role of protecting the imagedisplay layer 220 b from being damaged. The release protective layer 227may be, for example, those mentioned for the release layer 222 b. Whenthe resin layer 228 has a function of a release layer, the releaseprotective layer 227 can be omitted.

The resin layer 228 has a light-transmitting property, and istransparent in a typical case. The resin layer 228 plays a role ofgiving sufficient strength to the above underlayer. The material of theresin layer 228 may be, for example, thermosetting resin, photo-curableresin, or thermoplastic resin. When a thermosetting resin is used, thisresin layer 228 can be used as an adhesive layer for bonding the imagedisplay 22 to the cover sheet main body 21.

The resin layer 228 may include at least one of hologram and diffractiongrating as a diffraction structure. For example, a relief structure maybe provided as a diffraction structure on the surface of the resin layer228. In this case, the image displayed by this diffraction structure andthe image I1 b displayed by the image display layer 220 b are superposedon each other or arranged side by side.

The laminated body 202 may further include a patterned metal reflectionlayer such as an opaque metal reflection layer. For example, a patternedmetal reflection layer may be provided on the resin layer 228 or betweenthe release protective layer 227 and the resin layer 228, and dots, linescreen, other figures, or a combination thereof may be displayed on thismetal reflection layer. Such pattern can be used for, for example, theauthenticity check of the image display 22 or the labeled article 100.

Subsequently, the image display layer 220 b having the patterncorresponding to the above facial image is formed on the laminated body202. More specifically, based on the above image information, a part ofthe transfer material layer 220 b is thermally transferred from thesupport body 221 shown in FIG. 41 onto the resin layer 228 shown in FIG.43 as the image display layer 220 b. This thermal transfer is performedusing a thermal head in such a manner that a part of the transfermaterial layer 220 b thermally transferred onto the resin layer 228 hasthe pattern corresponding to the above facial image. As a result, thesecondary transfer foil 203 including the support body 226, the releaseprotective layer 227, the resin layer 228, and the image display layer220 b is obtained. The secondary transfer foil 203 is, for example, atransfer ribbon.

The image display layer 220 b thus obtained is formed by thermaltransfer using a thermal head, and therefore, in a typical case, itincludes a plurality of dot-shaped portions shown in FIGS. 39 and 40.The center of each of these dot-shaped portions is located on a latticepoint of a virtual planar lattice indicated by broken lines in FIG. 39.

In FIG. 39, the above planar lattice is a square lattice. However, theplanar lattice may be other lattices such as a triangular lattice and arectangular lattice. In FIG. 39, dot-shaped portions juxtaposed to eachother are arranged such that the outlines thereof are in contact witheach other at one point. In other words the diameter of each dot-shapedportion is equal to the minimum center-to-center distance of thedot-shaped portions. The adjacent dot-shaped portions may be placed awayfrom each other. In other words, the diameter of each dot-shaped portionmay be smaller than the minimum center-to-center distance of thedot-shaped portions. Alternatively, the adjacent dot-shaped portions maybe arranged as if they partially overlap each other. In other words, thediameter of each dot-shaped portion may be larger than the minimumcenter-to-center distance of the dot-shaped portions.

The diameter of the dot-shaped portion or the minimum center-to-centerdistance of the dot-shaped portions is within a range of, for example,0.085 to 0.508 mm (about 300 to about 50 dots per inch). When the facialimage is displayed by the image display layer 220 b, the diameter of thedot-shaped portion or the minimum center-to-center distance of thedot-shaped portions is within a range of, for example, 0.085 to 0.169 mm(about 300 to about 150 dots per inch). When this size is increased, itis difficult to display a high-resolution image on the image displaylayer 220 a. When this size is reduced, the reproducibility of thepatterned shape of the image display layer 220 b decreases.

As shown in FIG. 8, in the used primary transfer foil 201, a part of thetransfer material layer 220 b remains as a negative pattern of the imagedisplay layer 220 b shown in FIG. 43. This negative pattern can be usedto check up the image display layer 220 b.

In addition to forming the image display layer 220 b on the releaseprotective layer 227 using a part of the primary transfer foil 201, apattern indicating the non-biometric personal information and historyinformation such as date and time at which the image display layer 220 bare formed may be thermally transferred onto a separately-preparedsubstrate using another part of the primary transfer foil 201. As aresult, the used primary transfer foil 201 can be utilized not only forcheckup of the image display layer 220 b but also for checkup of otherinformation.

Before the image display layer 220 b is formed, another layer may beformed on the resin layer 228 or between the release protective layer227 and the resin layer 228. For example, on the resin layer 228 orbetween the release protective layer 227 and the resin layer 228, areflection layer, hologram and/or diffraction grating, or both of themmay be formed.

This reflection layer may be a continuous film, or may be patterned. Inthe latter case, the pattern of the reflection layer may be dots, linescreens, figures, or a combination thereof. This reflection layer mayhave a light-transmitting property, or may be opaque. Typically, thishologram and/or diffraction grating has optical characteristicsdifferent from those of the hologram and/or diffraction grating includedin the diffraction structure formation layer 223.

The image display layer 220 a shown in FIGS. 37 and 38 is further formedon the resin layer 228 or between the release protective layer 227 andthe resin layer 228. When the image display layer 220 a is formed on theresin layer 228, the image display layer 220 a may be formed before theimage display layer 220 b is formed on the resin layer 228, or may beformed on the resin layer 228 after the image display layer 220 b isformed on the resin layer 228.

When the image display layer 220 a is formed by thermal transfer method,sublimation transfer method or hot-melt transfer method may be employed.Alternatively, both of them may be employed. The image displayed by theimage display layer 220 a may be a monochrome image or a color image. Inthe latter case, the image display layer 220 a can be obtained by, forexample, using one or more ink ribbons to form colored layers in fourcolors, i.e., yellow, magenta, cyan, and black, or form colored layersin three colors, i.e., red, green, and blue.

A layer (not shown) displaying the image I3 shown in FIG. 1 may befurther formed on the resin layer 228 or between the release protectivelayer 227 and the resin layer 228. When the layer displaying the image13 is formed on the resin layer 228, this layer may be formed before theimage display layer 220 b is formed on the resin layer 228, or may beformed after the image display layer 220 b is formed on the resin layer228. Alternatively, the layer displaying the image I3 may be formed onthe cover sheet main body 21 instead of forming it on the resin layer228 or between the release protective layer 227 and the resin layer 228.The layer displaying the image I3 may be formed by, for example, thesame method as that described for the image display layer 220 a.

Subsequently, a part of the transfer material layer formed on thesupport body 226 that is used as the image display 22 is thermallytransferred from the support body 226 onto the cover sheet main body 21shown in FIGS. 38 and 40. This thermal transfer uses, for example, hotstamp. Instead of thermal transfer using the hot stamp, thermal transfermay be performed using a heat roll or a thermal head. As describedabove, the image display 22 is adhered to the cover sheet main body 21.

The layer displaying the image I3 may be formed on the cover sheet mainbody 21 as described above. An adhesive anchor layer may be formed onthe cover sheet main body 21 in order to enhance the adhesion strength.

When it is difficult to bond the image display 22 to the cover sheetmain body 21 with high adhesion strength, and the image display layer220 a is formed after the image display layer 220 b is formed, an inkribbon additionally having a function of an adhesion ribbon may be used.In this case, it is not necessary to use an adhesion ribbon in additionto the ink ribbon.

As described above, after the image display 22 is thermally transferredonto the cover sheet main body 21, necessary steps are appropriatelycarried out. In this manner, the labeled article 100 described withreference to FIGS. 36 to 40 is obtained.

In this method, the image display layer 220 b is formed by thermaltransfer using a thermal head. The precision that can be achieved withuse of a thermal head is higher than the precision that can be achievedby printing of pearl pigment.

When the image display layer 220 b is directly formed on the cover sheetmain body 21 by thermal transfer using a thermal head, it is difficultto achieve high image quality due to roughness of the surface of thecover sheet main body 21. In contrast, in the above method, the imagedisplay layer 220 a is not directly formed on the cover sheet main body21. In other words, in this method, first, the image display layer 220 ais formed on the release protective layer 227, and thereafter,transferred onto the cover sheet main body 21 together with the releaseprotective layer 227. Therefore, the image quality is not greatlyaffected by the surface roughness of the cover sheet main body 21 andthe like.

Therefore, according to this method, high quality image can be displayedby the image display layer 220 b.

This image display 22 displays a piece of personal information using thehologram and/or diffraction grating. It is extremely difficult to tamperwith the personal information, in particular biometric information,displayed by the hologram and/or the diffraction grating.

In this method, the image display 22 is supported by the cover sheetmain body 21 by thermal transfer. Such image display 22 is easilydestroyed when it is released from the cover sheet main body 21.Therefore, it is difficult to tamper with information on this labeledarticle 100.

Subsequently, a modification of the labeled article 100 described withreference to FIGS. 36 to 39 will be described.

FIG. 45 is a plan view schematically showing an example of a diffractionstructure that can be employed in the image display of the labeledarticle shown in FIGS. 36 to 39. FIG. 46 is a plan view schematicallyshowing an example of a diffraction structure that can be used incombination with the diffraction structure shown in FIG. 45. FIG. 47 isa plan view schematically showing an example of an arrangement of thediffraction structure shown in FIGS. 45 and 46.

In A labeled article 100 according to the modification, an image displaylayer 220 b includes sub-pixels CO_(R) and CO_(L). The sub-pixels CO_(R)and CO_(L) have the same structure as the structure described withreference to FIG. 9.

The pixel group including the sub-pixels CO_(R) displays a firstsub-image as a diffraction image when observed in a first directionunder particular illumination conditions, and when observed in a seconddirection different from the first direction under the illuminationconditions, the pixel group does not display the first sub-image as adiffraction image or displays the first sub-image as a diffraction imagedarker as compared with the case where observed in the first direction.Here, the pixel group including the sub-pixels CO_(R) emits diffractedlight in the right direction.

The pixel group including the sub-pixels CO_(L) displays a secondsub-image as a diffraction image when observed in a second directionunder the above illumination conditions, and when observed in the firstdirection under the illumination conditions, the pixel group does notdisplay the second sub-image as the diffraction image or displays thesecond sub-image as a diffraction image darker as compared with the casewhere observed in the second direction. Here, the pixel group includingthe sub-pixels CO_(L) emits diffracted light in the left direction.

In this modification, different images are displayed by the pixel groupincluding the sub-pixels CO_(L) and the pixel group including thesub-pixels CO_(L) as described later. For example, the facial image isdisplayed by one of the pixel groups, and an image other than the facialimage such as characters and symbols is displayed by the other of thepixel groups. In this case, the observer perceives different images whenobserving in the first direction and when observing in the seconddirection.

It should be noted that the grooves G are curved in the sub-pixelsCO_(R) and CO_(L) shown in FIGS. 45 and 46. The grooves G may be instraight shape. However, the grooves G in curved shape provide a viewingzone wider than that provided by the grooves G in straight shape.Therefore, in the former case, when observed in a particular direction,both of the first and second images can be seen.

In FIG. 47, a row including sub-pixels CO_(R) and a row includingsub-pixels CO_(L) are arranged alternately. The arrangement of thesub-pixels CO_(R) and CO_(L) may be different from that shown in FIG.47.

FIG. 48 is a plan view schematically showing another example of anarrangement of the diffraction structure shown in FIGS. 45 and 46.

In FIG. 48, the sub-pixels CO_(R) and CO_(L) are alternately arranged ineach of the X direction and the Y direction. In other words, thearrangement of the sub-pixels CO_(R) and CO_(L) forms a checkeredpattern.

As above, various arrangements can be employed for the sub-pixels CO_(R)and CO_(L).

FIG. 49 is a plan view schematically showing an example of an imagedisplay that employs the arrangement shown in FIG. 48. FIG. 50 is a planview schematically showing an image displayed by the image display shownin FIG. 49. FIG. 51 is a plan view schematically showing another imagedisplayed by the image display shown in FIG. 49.

In FIG. 49, the sub-pixels CO_(R) are arranged in a circle, and thesub-pixels CO_(L) are arranged in a cross shape. As shown in FIG. 50,when the image display 22 is observed in the right direction, thecircular pattern displayed by the pixel group including the sub-pixelsCO_(R) can be seen as a diffraction image. On the other hand, as shownin FIG. 51, when the image display 22 is observed in the left direction,the cross-shaped pattern displayed by the pixel group including thesub-pixels CO_(L) can be seen as a diffraction image. As shown in FIG.49, when the image display 22 is observed in the front direction, bothof the circular pattern and the cross-shaped pattern can be seen as adiffraction image.

FIG. 52 is a plan view schematically showing an example of an image thatcan be displayed by an image display employing the arrangement shown inFIG. 48. FIG. 53 is a plan view schematically showing another example ofan image display that employing the arrangement shown in FIG. 48. FIG.54 is a plan view schematically showing still another example of animage display that employing the arrangement shown in FIG. 48.

The image I1 b 1 shown in FIG. 52 is, for example, an image displayed bythe pixel group including the sub-pixels CO_(R). The image I1 b 2 shownin FIG. 53 is, for example, an image displayed by the pixel groupincluding the sub-pixels CO_(L). Here, the image I1 b 1 is a facialimage, and the image I1 b 2 is a microscopic image constituted by acharacter string “JAPAN”. The size of each character constituting theimage I1 b 2 is, for example, 300 μm or more. That is, each characterconstituting the image I1 b 2 can be seen with unaided eyes.

In the case of employing this configuration, when the image display 22is observed in the right direction, the facial image I1 b 1 shown inFIG. 52 can be seen. On the other hand, when the image display 22 isobserved in the left direction, the character string 11 b 2 shown inFIG. 53 can be seen. When the image display 22 is observed in the frontdirection, the image I1 b 3 shown in FIG. 54 can be seen. In otherwords, the image I1 b 3 obtained by superposing the facial image I1 b 1shown in FIG. 52 and the character string 11 b 2 shown in FIG. 53 oneach other can be seen.

Therefore, in the case where the labeled article 100 is, for example, apassport and the microscopic image I1 b 2 includes a character string orsymbol displaying an issuing country, authenticity check can be made ona passport whose authenticity is unknown by confirming this microscopicimage I1 b 2. In the case where the labeled article 100 is an ID cardand the microscopic image I1 b 2 includes a character string or symbolindicating an affiliation, an authenticity check can be made on an IDcard whose authenticity is unknown by confirming this microscopic imageI1 b 2.

Here, as an example, the relief structure is described as a diffractiongrating. However, other relief structures such as hologram andlight-scattering structure having anisotropic light-scattering propertymay be used instead of the diffraction grating. Even in such cases, theviewing zone for the image to be displayed can be limited. Therefore,the observer can perceives different images by changing the observationdirection.

Fourth Embodiment

The fourth embodiment is related to, for example, the followingtechniques.

(1) An image display including pixel groups each including pixels,wherein each of the of pixels includes grooves having the samelengthwise directions and emitting at least one of a diffracted lightand a scattered light having directivity when irradiated withillumination light, the lengthwise directions of the pixels being thesame in each of the pixel groups, the pixel groups being different inthe lengthwise directions, the pixel groups displaying respectivesub-images, and the sub-images have different sizes and have the sameshape.(2) The image display according to the item (1), wherein the grooves arein curved shape.(3) The image display according to the item (2), wherein the maximumvalue of the angles that tangents to the grooves in one of the pixelgroups form with a reference direction parallel to the display surfaceis equal to the minimum value of the angles that tangents to the groovesin another of the pixel groups form with the reference direction.(4) The image display according to any one of the items (1) to (3),wherein the center positions of the sub-images are the same.(5) The image display according to any one of the items (1) to (3),wherein the center positions of the sub-images are different.(6) The image display according to any one of the items (1) to (5),wherein three or more pixel groups are provided, and the sizes of thethree or more pixel groups are in relationship of arithmeticprogression.(7) The image display according to any one of the items (1) to (6),wherein the sub-images are images including personal information.(8) The image display according to the item (7), wherein the imageincluding the personal information is a facial image.(9) The image display according to any one of the items (1) to (8),comprising a first image-displaying portion that displays firstinformation about a certain object as a first image of object color, anda second image-displaying portion that displays second information aboutthe object as a second image of structural color provided by a reliefstructure, wherein the second image-displaying portion includes thepixel groups.(10) A labeled article comprising the image display according to any oneof the items (1) to (9), and a substrate supporting the image display.(11) The labeled article according to the item (10), wherein the labeledarticle is an individual authentication medium.

The effects of the techniques according to the items (1) to (11) will beindividually described.

In the image display according to the item (1), each pixel includesgrooves whose lengthwise directions are the same and which emit at leastone of a diffracted light and a scattered light having directivity whenirradiated with illumination light. The color of the image displayed bythe diffracted light changes according to the observation direction. Onthe other hand, the brightness of the image displayed by the scatteredlight having directivity changes according to the observation direction.

In each pixel group, the pixels have the same lengthwise direction ofthe grooves. The pixel groups are different from each other in thelengthwise directions of the grooves and display respective sub-images.These sub-images have different sizes and have the same shape. When thisconfiguration is employed, a motion picture can be displayed using oneoriginal image. Specifically, when the observation direction is changed,the size of the image changes.

In this manner, this image display provides special visual effects. Inaddition, it is extremely difficult to tamper with the informationdisplayed by the structure providing this visual effect.

In the image display according to the item (2), the grooves are incurved shape. The grooves in curved shape provide a viewing zone widerthan that provided by grooves in straight shape. Therefore, in theformer case, the image can change more smoothly than in the latter case.

In the image display according to the item (3), the maximum value of theangles that tangents to the grooves in one of the pixel groups form witha reference direction parallel to the display surface is equal to theminimum value of the angles that tangents to the grooves in another ofthe pixel groups form with the reference direction. When thisconfiguration is employed, the image changes more smoothly.

In the image display according to the item (4), the center positions ofthe sub-images are the same. In the case of employing thisconfiguration, when the observation direction is changed, the imageappears to move in the forward or backward direction.

In the image display according to the item (5), the center positions ofthe sub-images are different. In the case of employing thisconfiguration, when the observation direction is changed, the imageappears to move in a diagonal direction with respect to the displaysurface.

The image display according to the item (6) has three or more pixelgroups. The sizes of the pixel groups are in relationship of arithmeticprogression. In this case, the image can change more smoothly than in acase where the number of pixel groups is two.

In the image display according to the item (7), sub-images are imagesincluding personal information. In this case, it is difficult tocounterfeit the image display, and in addition, the image display can beused for individual authentication.

In the image display according to the item (8), the image including thepersonal information is a facial image. The facial image is suitable forindividual authentication.

The image display according to the item (9) comprises a firstimage-displaying portion that displays first information about a certainobject as a first image of object color, and a second image-displayingportion that displays second information about the object as a secondimage of structural color provided by a relief structure. The secondimage-displaying portion includes the pixel groups. The first image ofobject color has excellent visibility.

The labeled article according to the item (10) includes the imagedisplay according to any one of the items (1) to (9), and a substratesupporting the image display. Therefore, in the labeled article, highquality image is displayed by the image display, and in addition, it isdifficult to tamper with the information recorded on the image display.

The labeled article according to the item (11) is an individualauthentication medium. Since the individual authentication mediumincludes the above image display, the individual authentication mediumachieves excellent anti-counterfeiting effects.

Subsequently, the fourth embodiment will be described with reference todrawings.

A labeled article according to the fourth embodiment is the same as thelabeled article 100 according to the first embodiment except that thelabeled article according to the fourth embodiment employs aconfiguration capable of displaying a moving image as an image I1 b.First, a principle for displaying the moving image will be described.

FIG. 55 is a plan view schematically showing an example of an imagedisplay that employs a configuration similar to an image displayaccording to the fourth embodiment of the present invention. FIG. 56 isa plan view schematically showing one of the images displayed by theimage display shown in FIG. 55. FIG. 57 is a plan view schematicallyshowing another image displayed by the image display shown in FIG. 55.

The image display 22 b shown in FIG. 55 is the same as a part of theimage display 22 described with reference to FIGS. 1 to 5 thatcorresponds to the image I1 b except that it employs the followingconfiguration. That is, in this image display 22 b, the image displaylayer 220 b includes the sub-pixels CO1 and CO2. Each of the sub-pixelsCO1 and CO2 has the same structure as the dot-shaped portion describedwith reference to FIGS. 4 and 5. The region around the sub-pixels CO1and CO2 have different visual effect from the sub-pixels CO1 and CO2.Here, as an example, each sub-pixels CO1 and CO2 is assumed to includediffraction grating.

The sub-pixels CO1 and CO2 are different in the lengthwise direction ofthe grooves of the diffraction grating. Here, as an example, thelengthwise direction of the grooves of the diffraction grating includedin the sub-pixel CO1 is assumed to be parallel to the X direction. Inaddition, in this case, for example, the lengthwise direction of thegroove of the diffraction grating included in the sub-pixel CO2 forms anangle of 30° in the counterclockwise direction with respect to the Xdirection. In FIG. 55, each of the sub-pixels CO1 and CO2 is depicted asa circle. However, the sub-pixels CO1 and CO2 may have other shapes suchas a square or rectangular shape.

When this image display 22 b is illuminated with the diffuse lightemitted by the light source LS, the sub-pixel CO1 emits the diffractedlight with the highest intensity in a direction perpendicular to the Xdirection. Also, in this case, the sub-pixel CO2 emits the diffractedlight with the highest intensity in a direction perpendicular to an axisthat forms an angle of 30° in the counterclockwise direction withrespect to the X direction.

Therefore, as shown in FIG. 56, the observer OB1 who observes the imagedisplay 22 b in a direction perpendicular to the X direction perceivesthe sub-image I1 b 1 displayed by the first pixel group including thesub-pixels CO1. In this case, the observer OB1 perceives a character“T”.

On the other hand, as shown in FIG. 57, an observer OB2 who observes theimage display 22 b in a direction perpendicular to the axis that formsthe angle of 30° in the counterclockwise direction with respect to the Xdirection perceives the sub-image I1 b 2 displayed by the second pixelgroup including the sub-pixels CO2. In this case, the observer OB2perceives a character “P”.

FIG. 58 is a plan view schematically showing one of the images that canbe displayed when the image display shown in FIG. 55 employs morecomplicated structure. FIG. 59 is a plan view schematically showinganother image that can be displayed by the image display displaying theimage shown in FIG. 58. FIG. 60 is a plan view schematically showinganother image that can be further displayed by the image displaydisplaying the image shown in FIG. 58.

FIGS. 58 to 60 show first to third sub-images displayed by the imagedisplay 22 b in which the image display layer 220 b includes first tothird sub-pixels.

The first to third sub-pixels are different in the lengthwise directionof the grooves of the diffraction grating. Here, as an example, thelengthwise direction of the groove of the diffraction grating includedin the first sub-pixels is assumed to be parallel to the X direction. Inaddition, in this case, for example, the lengthwise direction of thegroove of the diffraction grating included in the second sub-pixelsforms an angle of 30° in the counterclockwise direction with respect tothe X direction. Further, in this case, for example, the lengthwisedirection of the grooves of the diffraction grating included in thethird sub-pixels forms an angle of 60° in the counterclockwise directionwith respect to the X direction.

In this case, as shown in FIG. 58, the observer OB1 who observes theimage display 22 b in the direction perpendicular to the X directionperceives the first sub-image I1 b 1 displayed by the first pixel groupincluding the first sub-pixels. In this case, as shown in FIG. 59, theobserver OB2 who observes the image display 22 b in the directionperpendicular to the axis that forms the angle of 30° in thecounterclockwise direction with respect to the X direction perceives thesecond sub-image I1 b 2 displayed by the second pixel group includingthe second sub-pixels. Further, in this case, as shown in FIG. 60, anobserver OB3 who observes the image display 22 b in a directionperpendicular to an axis that forms an angle of 60° in thecounterclockwise direction with respect to the X direction perceives thethird sub-image I1 b 3 displayed by the third pixel group including thethird sub-pixels.

FIG. 61 is a plan view schematically showing an example of anarrangement of a diffraction structure that can be employed in the imagedisplay displaying the image shown in FIGS. 58 to 60. FIG. 62 is a planview schematically showing another example of an arrangement of adiffraction structure that can be employed in the image displaydisplaying the image shown in FIGS. 58 to 60. FIG. 63 is a plan viewschematically showing still another example of an arrangement of adiffraction structure that can be employed in the image displaydisplaying the image shown in FIGS. 58 to 60.

In the arrangement shown in FIG. 61, the first sub-pixels CO1 form aplurality of rows each extending in the Y direction and arranged in theX direction. The second sub-pixels CO2 form a plurality of rows eachextending in the Y direction and arranged in the X direction. The thirdsub-pixels CO3 form a plurality of rows each extending in the Ydirection and arranged in the X direction. The row of the firstsub-pixels CO1, the row of the second sub-pixels CO2, and the row of thethird sub-pixels CO3 are arranged in this order in the X direction.

In the arrangement shown in FIG. 62, the first sub-pixels CO1 form aplurality of rows each extending in the X direction and arranged in theY direction. The second sub-pixels CO2 form a plurality of rows eachextending in the X direction and arranged in the Y direction. The thirdsub-pixels CO3 form a plurality of rows each extending in the Xdirection and arranged in the Y direction. The row of the firstsub-pixels CO1, the row of the second sub-pixels CO2, and the row of thethird sub-pixels CO3 are arranged in this order in the Y direction.

In the arrangement shown in FIG. 63, the first sub-pixels CO1 form aplurality of rows each extending in a diagonal direction inclined withrespect to the X direction and arranged in the Y direction. The secondsub-pixels CO2 form a plurality of rows each extending in the abovediagonal direction and arranged in the Y direction. The third sub-pixelsCO3 form a plurality of rows each extending in the above diagonaldirection and arranged in the Y direction. The row of the firstsub-pixels CO1, the row of the second sub-pixels CO2, and the row of thethird sub-pixels CO3 are arranged in this order in the Y direction.

FIG. 64 is a plan view schematically showing an example of a structurethat can be employed in the image display of the labeled articleaccording to the fourth embodiment of the present invention. FIG. 65 isa plan view schematically showing one of the images displayed by theimage display shown in FIG. 64. FIG. 66 is a plan view schematicallyshowing another image displayed by the image display shown in FIG. 64.FIG. 67 is a plan view schematically showing still another imagedisplayed by the image display shown in FIG. 64.

The structure shown in FIG. 64 includes the first sub-pixels CO1, thesecond sub-pixels CO2, and the third sub-pixels CO3 described withreference to FIGS. 58 to 63.

The first sub-pixels CO1 are arranged in a quadrilateral form. The firstpixel group including the first sub-pixels CO1 forms a first pattern.

The second sub-pixels CO2 are arranged in a quadrilateral form. Thesecond pixel group including the second sub-pixels forms a secondpattern. The second pattern surrounds the first pattern. The centerpositions of the first and second patterns are the same.

The third sub-pixels CO3 are arranged in a quadrilateral form. The thirdpixel group including the third sub-pixels forms a third pattern. Thethird pattern surrounds the second pattern. The center positions of thesecond and third patterns are the same.

As shown in FIG. 65, when this configuration is employed, the observerOB1 who observes the image display 22 b in a direction perpendicular tothe X direction perceives the first sub-image I1 b 1 displayed by thefirst pixel group including the first sub-pixels CO1. In this case, asshown in FIG. 66, the observer OB2 who observes the image display 22 bin a direction perpendicular to the axis that forms an angle of 30° inthe counterclockwise direction with respect to the X direction perceivesthe second sub-image I1 b 2 displayed by the second pixel groupincluding the second sub-pixels CO2. Further, in this case, as shown inFIG. 67, the observer OB3 who observes the image display 22 b in adirection perpendicular to an axis that forms an angle of 60° in thecounterclockwise direction with respect to the X direction perceives thethird sub-image I1 b 3 displayed by the third pixel group including thethird sub-pixels CO3.

The sub-images I1 b 1 to 11 b 3 have a quadrilateral shape and havedifferent sizes. Specifically, the sub-image I1 b 2 is larger than thesub-image I1 b 1. The sub-image I1 b 3 is larger than the sub-image I1 b2.

When the angle that the orthogonal projection of the observationdirection on the XY plane forms with the X direction (hereinafter,referred to as “azimuth angle of the observation direction” or “azimuthangle”) is changed from −90° to −60° while the angle of the observationdirection with respect to the Z direction is kept constant, the imageperceived by the observer is changed from the sub-image I1 b 1 to thesub-image 11 b 2. When the azimuth angle of the observation direction isfurther changed from −60° to −30° while the angle of the observationdirection with respect to the Z direction is kept constant, the imageperceived by the observer changes from the sub-image I1 b 2 to thesub-image I1 b 3. In other words, by rotating the observation directionabout the axis parallel to the Z direction, the image perceived by theobserver changes in the order of the sub-image I1 b 1, the sub-image I1b 2, and then the sub-image I1 b 3, or changes in the order of thesub-image I1 b 3, the sub-image I1 b 2, and then the sub-image I1 b 1.Since the sub-images I1 b 1, 11 b 2, and 11 b 3 are geometricallysimilar, the observer can perceive the above change of the images as amotion picture. In this case, the center positions of the sub-images I1b 1 to 11 b 3 are the same, and therefore, when the azimuth angle of theobservation direction is changed, the image perceived by the observerappears to come closer to the observer, or appears to move away from theobserver.

FIG. 68 is a plan view schematically showing an example of an image thatcan be displayed when the image display of the labeled article accordingto the fourth embodiment of the present invention employs anotherstructure. FIG. 69 is a plan view schematically showing another imagethat can be displayed by the image display displaying the image shown inFIG. 68. FIG. 70 is a plan view schematically showing still anotherimage that can be displayed by the image display displaying the imageshown in FIG. 68.

In the structure described with reference to FIGS. 65 to 67, thesub-pixels CO1 to CO3 are arranged so that quadrilateral shapesub-images are displayed. When the number of sub-pixels CO1 to CO3increases, more complicated sub-images can be displayed. For example, asshown in FIGS. 65 to 67, facial images can be displayed as thesub-images I1 b 1 to 11 b 3.

It should be noted that three original images corresponding to thesub-images I1 b 1 to 11 b 3 are needed to manufacture the image display22 b displaying the sub-images I1 b 1 to 11 b 3 shown in FIGS. 58 to 60.These original images are generated using, for example, computergraphics. Then, based on these original images, the arrangement of thesub-pixels CO1 to CO3 is determined.

On the other hand, in order to manufacture the image display 22 bdisplaying the sub-images I1 b 1 to 11 b 3 shown in FIGS. 68 to 70, onlyone type of original image corresponding to one of the sub-images I1 b 1to 11 b 3 is necessary. Since the sub-images I1 b 1 to 11 b 3 aredifferent only in the sizes, the arrangement of the sub-pixels CO1 toCO3 can be determined based on the single original image. In this case,when the original image is obtained by taking a picture, this makes itunnecessary to generate the image using computer graphics.

The center positions of the sub-images I1 b 1 to 11 b 3 shown in FIGS.68 to 70 are the same. Therefore, when the azimuth angle of theobservation direction is changed, the image perceived by the observerappears to come closer to the observer, or appears to move away from theobserver.

The sizes of the sub-images I1 b 1 to 11 b 3 are, for example, inrelationship of numerical sequence.

The sizes of the sub-images I1 b 1 to 11 b 3 may be in relationship ofarithmetic progression. That is, the size of the pixel group includingthe sub-pixels CO1, the size of the pixel group including the sub-pixelsCO2, and the size of the pixel group including the sub-pixels CO3 may bein relationship of arithmetic progression. For example, the size of thesub-image I1 b 1 is set at 50% of the size of the sub-image I1 b 3, andthe size of the sub-image I1 b 2 is set at 75% of the size of thesub-image I1 b 3.

In this case, when the azimuth angle of the observation direction ischanged at a constant rate, the image perceived by the observer appears,for example, to come closer to the observer at a constant velocity.Alternatively, when the azimuth angle of the observation direction ischanged at a constant rate, the image appears to move away from theobserver at a constant velocity.

The sizes of the sub-images I1 b 1 to 11 b 3 may be in relationship ofgeometric progression. That is, the size of the pixel group includingthe sub-pixels CO1, the size of the pixel group including the sub-pixelsCO2, and the size of the pixel group including the sub-pixels CO3 may bein relationship of geometric progression.

In this case, when the azimuth angle of the observation direction ischanged at a constant rate, the image perceived by the observer appearsto, for example, come closer to the observer at a constant acceleration.Alternatively, when the azimuth angle of the observation direction ischanged at a constant rate, the image appears to move away from theobserver at a constant acceleration.

In the above image display 22, the grooves of the diffraction gratingincluded in the sub-pixel may have curved shapes. In this case, asdescribed below, the image can change more smoothly as compared with thecase where the grooves of the diffraction grating have straight shapes.

FIG. 71 is a view schematically showing an example of conditions underthat allow images to be perceived when the grooves of the diffractiongrating have straight shapes.

The image display 22 b shown in FIG. 71 includes the sub-pixels CO1 andCO3 described with reference to FIGS. 61 to 63. The grooves of thediffraction gratings included in the sub-pixels CO1 have straight shapeswhose lengthwise directions are parallel to the X direction. On theother hand, the grooves of the diffraction gratings included in thesub-pixels CO1 have straight shapes whose lengthwise directions forms anangle of 60° in the counterclockwise direction with respect to the Xdirection.

When this configuration is employed, an observer OB1 who observes theimage display 22 b in a direction perpendicular to the X directionperceives a sub-image displayed by the pixel group including thesub-pixels CO1, character “T” here. In this case, an observer OB3 whoobserves the image display 22 b in a direction perpendicular to an axisthat forms an angle of 60° in the counterclockwise direction withrespect to the X direction perceives a sub-image displayed by the pixelgroup including the sub-pixels CO3, character “P” here. However, anobserver OB2 who observes the image display 22 b in a directionperpendicular to the axis that forms the angle of 30° in thecounterclockwise direction with respect to the X direction hardlyperceives or does not perceive the sub-images.

FIG. 72 is a view schematically showing an example of conditions thatallow images to be perceived when the grooves of the diffraction gratingare curved lines. FIG. 73 is an enlarged plan view showing one of thediffraction structures included in the image display shown in FIG. 72.FIG. 74 is an enlarged plan view showing another diffraction structureincluded in the image display shown in FIG. 72.

The image display 22 b shown in FIG. 72 includes sub-pixels CO12 andCO23. The sub-pixels CO12 and CO23 are the same as the sub-pixels CO1and CO3 except that the grooves of the diffraction gratings havedifferent shapes.

As shown in FIG. 73, each of the grooves G12 of the diffraction gratingsincluded in the sub-pixels CO12 has a curved shape. The grooves G12 arearranged in parallel to each other. The angle that a tangent to thegroove G12 forms with the X direction continuously changes from 0° to30°. Therefore, the sub-pixel CO12 emits diffracted light withrelatively high intensity over the entire range of the azimuth anglefrom −90° to −60°.

As shown in FIG. 74, each of the grooves G23 of the diffraction gratingsincluded in the sub-pixels CO23 has a curved shape. The grooves G23 arearranged in parallel to each other. The angle that a tangent to thegroove G23 forms with the X direction continuously changes from 30° to60°. Therefore, the sub-pixel CO23 emits diffracted light withrelatively high intensity over the entire range of the azimuth anglefrom −60° to −30°.

As described above, the grooves of the diffraction grating in curvedshapes provides wider viewing zone than grooves in straight shapes.Therefore, the image is less likely to be perceived by the observer, orthe range of the azimuth angle in which the image is not perceived canbe reduced. In particular, when the maximum value of the angles that thetangents to the groove G12 form with the X direction is substantiallyequal to the minimum value of the angles that the tangents to the grooveG23 form with the X direction, the range of the azimuth angle in which aplurality of images are seen to overlap each other can be set atsubstantially zero, and the range of the azimuth angle in which theobserver hardly perceives or does not perceive the image can be set atsubstantially zero.

The image display 22 described with reference to FIGS. 72 to 74 can bemodified in various forms.

FIG. 75 is an enlarged plan view showing one of the diffractionstructures that can be included in the image display according to amodification. FIG. 76 is an enlarged plan view showing anotherdiffraction structure that can be included in the image displayincluding the diffraction structure shown in FIG. 75.

In the sub-pixel CO12 shown in FIG. 75, each of the grooves G12 of thediffraction grating has a curved shape. The grooves G12 are arranged inparallel to each other. The angle that a tangent to the groove G12 formswith the X direction continuously changes from 0° to 45°. Therefore, thesub-pixel CO12 emits diffracted light with relatively high intensityover the entire range of the azimuth angle from −90° to −45°.

In the sub-pixel CO23 shown in FIG. 76, each of the grooves G23 of thediffraction grating has a curved shape. The grooves G23 are arranged inparallel to each other. The angle that a tangent to the groove G23 formswith the X direction continuously changes from 30° to 75°. Therefore,the sub-pixel CO23 emits diffracted light with relatively high intensityover the entire range of the azimuth angle from −60° to −15°.

Therefore, within the range of the azimuth angle from −60° to −45°, bothof the image displayed by the sub-pixels CO12 and the image displayed bythe sub-pixels CO23 are perceived. The images are seen to overlap eachother within the range of the azimuth angle from −60° to −45°.

FIG. 77 is a plan view schematically showing one of the images that canbe displayed by the image display according to another modification.FIG. 78 is a plan view schematically showing another image that can bedisplayed by the image display displaying the image shown in FIG. 77.FIG. 79 is a plan view schematically showing another image that can befurther displayed by the image display displaying the image shown inFIG. 77.

The image display according to the modification is the same as the imagedisplay described with reference to FIGS. 68 to 70 except that thesub-images I1 b 1 to 11 b 3 are configured to have centers at differentpositions. That is, in the image display according to the modification,the pixel group including the sub-pixels CO1, the pixel group includingthe sub-pixels CO2, and the pixel group including the sub-pixels CO3have centers at different positions. For example, the center of thesub-image I1 b 2 is located in the middle between the center of thesub-image I1 b 1 and the center of the sub-image I1 b 3. In this case,when the azimuth angle of the observation direction is changed, theimage perceived by the observer appears to come diagonally closer to theobserver, or appears to move diagonally away from the observer.

A first vector from the center of the sub-image I1 b 1 to the center ofthe sub-image I1 b 2 may be the same as or different from a secondvector from the center of the sub-image I1 b 2 to the center of thesub-image I1 b 3. In the latter case, the first and second vectors mayhave the same senses and different magnitudes. Alternatively, the firstand second vectors may have different senses and the same magnitudes.Alternatively, the first and second vectors may have different sensesand different magnitudes.

For example, when the magnitudes of the first and second vectors are thesame, and the azimuth angle of the observation direction is changed at aconstant rate, the image perceived by the observer appears to be movingat a constant velocity in one or more directions perpendicular to the Zdirection. When the magnitudes of the first and second vectors aredifferent, and the azimuth angle of the observation direction is changedat a constant rate, the movement of the image perceived by the observerin one or more directions perpendicular to the Z direction appears to bedecelerating or accelerating.

For the sake of simplicity, described above were cases where the imagedisplay layer 220 b includes three kinds or less sub-pixels. Asexemplified below, the image display layer 220 b may be constituted bymore kinds of sub-pixels.

The image display 22 b similar to the one described with reference toFIGS. 68 to 70 was manufactured. Here, the image display layer 220 bincluded first to eighth sub-pixels below. Each of the first to eighthsub-pixels had a square shape of side 42 μm and included a diffractiongrating with curved grooves.

The first sub-pixel was designed to emit diffracted light withrelatively high intensity over the entire range of the azimuth anglefrom −112.88° to −107.16°. The second sub-pixel was designed to emitdiffracted light with relatively high intensity over the entire range ofthe azimuth angle from −107.16 to −101.44°. The third sub-pixel wasdesigned to emit diffracted light with relatively high intensity overthe entire range of the azimuth angle from −101.44° to −95.72°. Thefourth sub-pixel was designed to emit diffracted light with relativelyhigh intensity over the entire range of the azimuth angle from −95.72°to −90°. The fifth sub-pixel was designed to emit diffracted light withrelatively high intensity over the entire range of the azimuth anglefrom −90° to −84.28°. The sixth sub-pixel was designed to emitdiffracted light with relatively high intensity over the entire range ofthe azimuth angle from −84.28° to −78.56°. The seventh sub-pixel wasdesigned to emit diffracted light with relatively high intensity overthe entire range of the azimuth angle from −78.56° to −72.84°. Theeighth sub-pixel was designed to emit diffracted light with relativelyhigh intensity over the entire range of the azimuth angle from −72.84°to −67.12°.

The first sub-pixels were arranged to display a facial image as a firstsub-image. The second sub-pixels are arranged to display a secondsub-image with a size 1.05 times larger than the first sub-image andhaving a center at the same position as that of the first sub-image. Thethird sub-pixels were arranged to display a third sub-image with a size1.10 times larger than the first sub-image and having a center at thesame position as that of the first sub-image. The fourth sub-pixels werearranged to display a fourth sub-image with a size 1.15 times largerthan the first sub-image and having a center at the same position asthat of the first sub-image. The fifth sub-pixels were arranged todisplay a fifth sub-image with a size 1.20 times larger than the firstsub-image and having a center at the same position as that of the firstsub-image. The sixth sub-pixels were arranged to display a sixthsub-image with a size 1.25 times larger than the first sub-image andhaving a center at the same position as that of the first sub-image. Theseventh sub-pixels were arranged to display a seventh sub-image with asize 1.30 times larger than the first sub-image and having a center atthe same position as that of the first sub-image. The eighth sub-pixelswere arranged to display an eighth sub-image with a size 1.35 timeslarger than the first sub-image and having a center at the same positionas that of the first sub-image.

When this image display 22 b was observed while the azimuth angle of theobservation direction was changed, the facial image appeared to comecloser or appeared to move away.

Here, as an example, the diffraction grating is shown as the reliefstructure. However, other relief structures such as hologram andlight-scattering structure having anisotropic light-scattering propertymay be used instead of the diffraction grating. Even in such cases, theviewing zone of the image to be displayed can be limited. Therefore, theobserver can see a moving image by changing the observation direction.

The techniques described in the first to the fourth embodiments can becombined with each other. Some of matters described in a certainembodiments may be replaced with matters described in anotherembodiment.

In the first to the fourth embodiments, a passport is described as anexample of a labeled article. The techniques described above can also beapplied to an individual authentication medium other than the passport.For example, the above technique can also be applied to an accreditationcard used in an event such as Olympic and to a credit card.

The size of the labeled article is not limited. When the labeled articleis used for the individual authentication, it is desirable to easilycarry the labeled article. The size of an accreditation card used in anevent such as Olympic is, for example, about 95 mm×about 150 mm. Thesize of the data page of the passport is, for example, about 125mm×about 88 mm. The size of the credit card is, for example, about 86mm×about 54 mm.

The shape of the article supporting the image display is not limited.However, in general, this article includes a layer as a booklet or cardsubstrate includes. The thickness of this layer is, for example, withina range of 20 μm to 2,000 μm. Typically, the thickness of this layer iswithin a range of 50 μm to 1,000 μm.

The image display can be supported by, for example, a paper such asplain paper, coated paper, and synthetic paper. The synthetic paper is alayer including, for example, plastics such as polystyrene andpolypropylene and an inorganic filler such as calcium carbonate.Alternatively, the synthetic paper is a composite material includingsuch a layer and a plain paper.

The image display may be supported by a layer made of plastics such aspolyvinyl chloride, polyethylene terephthalate, and polyethylenenaphthalate. Alternatively, the image display may be supported by alayer made of ceramics.

A region of the surface of the article that supports the image displaymay have a single color throughout the entire region. Alternatively,this region may include a plurality of sub-regions having colorsdifferent from each other. In view of the visibility of the imagedisplayed by the image display, the above region may be applied withwhite color using white pigment such as titanium white, magnesiumcarbonate, zinc oxide, barium sulfate, silica, talc, clay, or calciumcarbonate.

The above technique can be used for authentication other than theindividual authentication. In other words, the above technique may beused for authentication of a living body other than a human, or may beused for authentication other than a living body. For example, the abovetechnique can be used for authentication other than a human such asanimals, plants, bacteria, security, industrial products, agriculturalproducts, marine foods, or art objects.

The above technique can also be used for purposes other than theauthentication. For example, the labeled article or the image displaycan be used as toys, ornaments, or learning materials.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventionconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. A labeled article comprising: an image display;and a substrate supporting the image display, wherein the image displaycomprises: a first image-displaying portion that displays firstinformation about a certain object as a first image of object color; asecond image-displaying portion that displays second information aboutthe object as a second image of structural color provided by a reliefstructure, the relief structure including at least one structureselected from the group consisting of diffraction grating and hologram;and an underlayer, the second image-displaying portion being provided onthe underlayer, wherein a reflection layer is formed on at least a partof a surface of the relief structure, the reflection layer being made ofmetal, metal oxide, or intermetallic compound, the secondimage-displaying portion is made of a plurality of dot-shaped portionsarranged in a two-dimensional manner, the object is a person, the firstimage includes a facial image of the person, and the second imageincludes a same facial image as the facial image included in the firstimage, and each of the dot-shaped portions includes: a relief structureformation layer facing the underlayer and having the relief structure ona surface thereof that faces the underlayer, the reflection layer atleast partially covering the relief structure, and an adhesive layerinterposed between the reflection layer-slayer and the underlayer. 2.The labeled article according to claim 1, wherein the labeled article isan individual authentication medium.